Which hypothesis states the method of measuring the outcome most clearly?

Correct answer: If water amount increases then plant height gain over seven days will be greater

The direct answer is B: if the water amount increases, plant height gain over seven days will be greater. A scientific hypothesis should state the factor being changed, the result being measured, and enough conditions to make the test clear. Option B identifies water amount as the independent variable, plant height gain as the dependent outcome, and seven days as the measurement period. “Height gain” means the change in height from the beginning to the end, so it is more useful than simply saying the plant will be better. Option A is vague because “better” has no agreed measurement or time period. Option B is correct because both the outcome and time are clearly specified, although the exact water amounts and other controlled conditions should also be stated in a full experiment. Option C is vague and gives no measurable result. Option D uses “happy,” a human feeling that cannot be measured consistently in a plant. A strong test would measure initial and final height, calculate the increase, and compare groups fairly. Memory cue: a good hypothesis names what changes, what is measured, and when.