In a particular experiment, a researcher monitored plant growth in one group of plants by
varying the amount of sunlight the plants were exposed to. Another group of plants received
the same amount of sunlight each day. He found that the amount of sunlight had a direct
effect on plant growth.

In this experiment, the independent variable is.

O group of plants that were exposed to different amounts of sunlight
O amount of sunlight
Oplant growth
O amount of fertilizer
Ogroup of plants that received the same amount of light each day