Answer:
A
Explanation:
The correct answer would laboratory experiment.
In the laboratory, variables can be controlled as much as possible using relevant equipment unlike in natural habitats or field experiments. For example, the amount of water that each plant would receive can be measured using measuring cylinders and the time they are applied can also be fixed.
Field and natural experiments require that experimental procedures are carried out in the field under natural conditions. Consequently, variables such as the amount of moisture that gets into the soil or the amount of light a plant will receive will be extremely difficult to control. Precipitation time and the duration of light can also not be controlled.
The correct option is, therefore, A.