easy 8th grade question!! I need help ASAP!

Question

anonymous · Answer

Emma went to a science fair. One of the students at the science fair performed an experiment to test the effects of music on plant growth. The student concluded from her results that music made plants grow approximately 10% faster. Which of the following questions should Emma ask the student to find out if the student's conclusion was valid?

I.	What types of plants were used in the experiment?
II.	What was the experiment's control?
III.	Was the experiment repeated more than once?

anonymous · Answer

A. I and II only
B. I, II, and III
C. II and III only
D. I only

maddisongruby · Answer

i wanna say its B or C, but i Cant remember witch one

anonymous · Answer

it is B