Answer:
C
Step-by-step explanation:
She hums happily and it must mean that she really likes painting. It can't be B. because we don't know if she could be in a painting class; she could be in her room or the park. A and D are about what she is going to draw or how she uses paint but we don't really know that so my best guess would be C is the correct answer.
Sorry if it's incorrect, but hope this helps!