Question

select those that include blinding.
in a study of risky behavior, an insurance company randomly selects patrons at randomly chosen drinking establishments. data are collected on the quantity of alcohol and tobacco products they consume, their dietary habits, and how much they exercise. the patrons are not told that the information is being collected by an insurance company.
in a study of how music affects concentration, participants are timed as they complete a logic puzzle either in a silent room or while listening to music. the researchers use randomization to determine what music, if any, the participant will listen to.
in a drug trial, participants are randomly assigned to receive either a new medication meant to lower cholesterol or a placebo, which they are to take daily. neither the participants nor the researchers are told which pills the participants are taking until the study ends.
in a study of differences between laundry detergents, participants are asked to use either a generic or name - brand detergent to wash their laundry. the researchers randomly assign the detergents, and the participants are not told which type they receive.
in a study of how differentiation is applied in general education classrooms, a team of researchers observes average students, gifted students, and students with special needs. they then compare the instructional methods used in their education. the teachers do not know that their instructional methods are being compared to student outcomes.

Explanation:

Blinding occurs when participants or researchers (or both) are unaware of certain aspects of the study to reduce bias. In the first option, patrons are unaware of the data - collector's identity. In the third option, both participants and researchers are unaware of the pill assignments (double - blind). In the fourth option, participants are unaware of the type of detergent they receive. In the fifth option, teachers are unaware that their instructional methods are being compared to student outcomes. The second option does not involve any form of blinding as there is no mention of participants or researchers being unaware of key aspects.

Answer:

In a study of risky behavior, an insurance company randomly selects patrons at randomly chosen drinking establishments. Data are collected on the quantity of alcohol and tobacco products they consume, their dietary habits, and how much they exercise. The patrons are not told that the information is being collected by an insurance company.
In a drug trial, participants are randomly assigned to receive either a new medication meant to lower cholesterol or a placebo, which they are to take daily. Neither the participants nor the researchers are told which pills the participants are taking until the study ends.
In a study of differences between laundry detergents, participants are asked to use either a generic or name - brand detergent to wash their laundry. The researchers randomly assign the detergents, and the participants are not told which type they receive.
In a study of how differentiation is applied in general education classrooms, a team of researchers observes average students, gifted students, and students with special needs. They then compare the instructional methods used in their education. The teachers do not know that their instructional methods are being compared to student outcomes.