In the cloth drying experiment what is the drying time?

Correct answer: Dependent variable

Direct answer: Option D is correct. In an experiment, the independent variable is deliberately changed, the dependent variable is measured as the result, and controlled variables are kept the same. In the cloth-drying experiment, drying time is the quantity measured after the drying conditions are arranged. Reasoning: a condition is varied; the cloth responds; the time taken to become dry is recorded. Because it is the outcome that depends on the experimental condition, it is the dependent variable. Option A is wrong because an independent variable is the factor changed by the investigator, not the recorded time. Option B is wrong because a controlled variable remains constant, such as cloth type or water amount. Option C is wrong because an observation is the act or record of noticing a result; the variable itself here is the measured time. Option D works because drying time is the measured outcome. Memory cue: changed = independent, measured result = dependent, kept same = controlled.