Question

what is the purpose of a control in an experiment? provides a basis for comparison provides tentative explanations for an observation provides a large sample size provides a small sample size provides wide range of variations in the independent variable

Explanation:

A control group in an experiment is kept under standard conditions without the test variable. Its core function is to serve as a reference point to measure the effect of the experimental variable by comparison. The other options describe functions unrelated to a control: tentative explanations are hypotheses, sample size relates to experimental design scale, and varying the independent variable is part of testing the experimental group.

Answer:

provides a basis for comparison