Question

a student wants to study the effect of sunlight on plant growth. in his experiment, 12 plants receive normal amounts of sunlight, but half of them are kept under bright sun lamps all night long. after 6 weeks, the plants’ heights are measured.

Explanation:

Since the problem is about an experiment studying the effect of sunlight on plant growth, the relevant subfield in Natural Science is Biology (specifically Plant Biology or Botany, but among the given subfields, Biology is the best fit).

The experiment focuses on plant growth and the effect of sunlight on it, which falls under the study of living organisms (plants) and their responses to environmental factors, a key area of Biology.

Answer:

The subfield is Biology (under Natural Science).