The answer would be B.
Why?
Because compounds are a combination of two or more elements, while a mixture can be virtually anything. We cannot simply mix hydroxide and sodium together and claim it as a physical bond, it doesn't make sense since they react with each other in some way. However, mixtures are typically physical, since a chemical change most likely would not occur if we mixed popcorn and pretzels together in a bowl to make chex mix.
I hope I could help and I hope this made sense!
