A company plans to develop a prototype weeding machine that

So the plan here is to develop a prototype of a machine that will be able to eliminate manual weeding. It will do that by determining which plants are weeds based on what shade of color they are and cutting only those plants. We want to *support* this plan. We can do this by selecting an answer choice that indicates that the machine will work the way it is supposed to.

A. This answer says that weeds come in a bunch of different shades. This would make it harder for the machine to determine which plants are weeds, meaning it may not be successful in getting all of the weeds. Eliminate.
B. This answer says that the shade of various plants changes over time. Like A, this would make it harder for the machine to determine which plants are weeds, which could lower its success. Eliminate.
C. This answer says that when people manually weed crops, they look at size and shape in addition to shade when determining which plants are weeds. This means that shade may not be enough to determine which plants are weeds. The machine only looks at shade, which mean that it may miss some weeds that are only distinguishable based on size and shape. Eliminate.
D. This answer says that we can select the color of plants that we grow without otherwise changing the plant. This means that we can manipulate the color of the crop plants to make them distinct from the weeds that grow around them. This would mean that all of the weeds would be a different shade than the crop plants, and the machine would be able to successfully cut them all. This works!
E. This answer choice talks about the season when weeding isn't necessary. We really only care about the season when weeding is necessary - what happens at other times of the year doesn't impact how well the machine works. This answer is out of scope. Eliminate.