Which of the following is the rationale behind why the weighted average method uses weight factors in conjunction with physical measures?

a$.$ Physical units $($measures$)$ alone provide the most reasonable allocation method.

b$.$ The market value of the joint process should be weighted more heavily toward one of the products.

c$.$ The net realizable value of one product is greater than that of another product made with the same joint process, so the allocation must be weighted accordingly.