observing changes in a single trial. testing for a desired trait. repeating steps in a procedure. controlling changes in conditions.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Scientists study the reaction of some bacteria to antibiotics, hoping to learn about a new strain of resistant bacteria. This method of gaining scientific knowledge is best described as
Possibilities:
- observing changes in a single trial.
- testing for a desired trait.
- repeating steps in a procedure.
- controlling changes in conditions.

testing for a desired trait.