Context: Malik is painting watercolor pictures with his friend. An hour after they have finished, Malik notices one painting is dry but the other is not. He wonders what factors affect how quickly watercolor paintings dry. So, he decides to design an experiment. He has the following supplies available:
two freshly painted watercolor pictures of the same size
his dining room table
a picnic table in his backyard
a heater
Using only these supplies, which question can Malik investigate with an experiment?
A. Do watercolor paintings dry faster when placed next to a fan?
B. Do watercolor paintings dry faster when they are placed inside or outside?
C. Does a large watercolor painting or a small watercolor painting dry faster?
Answer with the option's letter from the given choices directly.

B