One in which the reactants are in different phases is called

Heterogeneous

Explanation: Heterogeneous catalysts are catalysts that are in a different phase than the reactants. For example, the catalyst might be in the solid phase while the reactants are in a liquid or gas phase. A catalyst that is in the same phase as the reactants is called a homogeneous catalyst. Enzymes are an example of homogeneous catalysts, and acids can also be homogeneous catalysts.

explanation: it gains negative electrons, therefore becoming negatively charged. as charge cannot be created, nor destroyed, only transferred, this leaves the wool positive. now that they have opposite charges, the two items attract.

it is b that is the answer.