What is a difference between a law and a hypothesis?

a. a law describes how two variables affect each other, but a hypothesis only discusses one variable.
b. a law must be testable so that it can be proven, but a hypothesis is an untestable explanation.
c. a hypothesis includes an explanation for why two variables affect each other, but a law only describes how they affect each other.
d. a hypothesis may or may not be testable, but a law is an untestable explanation of why two variables affect each other and cannot be proven.