Question

1. what is the best definition of an acute illness or injury?

it has a very rapid onset but usually clears up in less than a month.
it has minor symptoms and develops slowly over years or even decades.
it is easily treated at home with rest and over - the - counter medications.
it is very serious and usually must be treated by a medical professional.

Explanation:

An acute illness or injury is characterized by a sudden onset. While some acute conditions can be severe (but not all require medical professionals as some like mild colds can resolve on their own), the key defining features are the rapid onset and relatively short - term duration (usually less than a month). The option about minor symptoms developing over years is for chronic conditions. The option about home treatment is too narrow as not all acute conditions are treated at home (e.g., acute appendicitis needs surgery), and the option about being very serious is incorrect as "acute" doesn't always mean "severe" in terms of requiring a medical professional (though some do).

Answer:

It has a very rapid onset but usually clears up in less than a month.