When customers have a long-list of desired features they want to include in a product, an effective and objective way to prioritize them is:
a. to ask customers to identify "must haves" and "wanna haves"
b. to let the project manager determine which features are high priority, which are middle priority, and which are low priority
c. to let the technical team review the features to determine which can and which cannot be achieved in the project's limited time frame
d. to employ the Poor Man's Hierarchy