Context: The passage below describes an experiment. Read the passage and then follow the instructions below.

Sidney planted 25 tomato seeds one-half inch below the soil surface in each of six pots. Sidney added an equal amount of fertilizer to three of the six pots. She placed the pots in a plant growth chamber where all the seeds experienced the same temperature, amount of light, and humidity level. After two weeks, Sidney counted the number of seedlings that grew in each pot. She compared the number of seedlings in the pots with fertilizer to the number of seedlings in the pots without fertilizer.
Figure: tomato seedlings growing in soil.
Identify the question that Sidney's experiment can best answer.
A. Do more tomato seedlings grow when they are planted in soil with fertilizer compared to soil without fertilizer?
B. Does the humidity level where tomato seeds are planted affect the number of tomato seedlings that grow?
Answer with the option's letter from the given choices directly.

A