If the buyer has a clear and unambiguous description or specification and wants to find out which supplier can deliver the best value when and where needed, he or she will typically issue a:

Request for quotation (RFQ).

Explanation:

A request for quotation is asking  for a price quotation. It is based on the premise that if the supplier can supply the good at the time and place required then the price is really the main decision point. For this to be true, the description must be clear and unambiguous so that each quote is for the same thing.

answer(b); ; ; the quantitative or qualitative variable for which the experimenter wishes to determine how its value is affected by the explanatory variable;