Which is a measurable question about plant growth?

Correct answer: How does the amount of water affect plant height?

Option B is measurable because the amount of water can be varied and the plant’s height can be measured in centimetres. It clearly identifies an independent variable (amount of water) and a dependent variable (plant height). In contrast, “beautiful” in option A is a personal opinion and cannot be measured objectively. Exam tip: Look for questions involving factors that can be changed and measured.