What is called a variable in a scientific experiment?

Correct answer: A factor that can change

The direct answer is C: a variable is a factor that can change or be measured in an experiment. In a simple plant investigation, the amount of water may be changed, plant growth may be measured, and sunlight or soil may be kept the same. The factor deliberately changed is often called the independent variable; the observed result is the dependent variable; factors kept unchanged are controlled variables. At this level, the key idea is simply that a variable can have different values. Option A is wrong because something that always remains the same is a control or constant, not a changing variable. Option B is wrong because an experiment title only names the investigation. Option C is correct because it gives the meaning of variable. Option D is wrong because a laboratory room is a place, not automatically a factor being changed or measured. Do not confuse every object in a laboratory with a variable: it becomes a variable only when its relevant value can change or be observed in the investigation. Memory cue: variable means “value can vary.”