Question

a study of sleep patterns randomly selected participants in the study to sleep in either a dark room or a room with light. which element of experiment design is known to be a part of this study? (1 point) randomization blinding replication

Explanation:

The study randomly selected participants and assigned them to sleep in different - light conditions. Randomization is the process of randomly assigning subjects to treatment groups, which is clearly present here. There is no mention of blinding (where participants or researchers are unaware of group assignments) or replication (repeating the experiment multiple times).

Answer:

randomization