Which term is defined as the maximum legal price for a good or service

The correct answer is price ceiling.

Explanation:

This price is set by the government establishing a limit on the highest price of a product, good, can be. To make sure it would not lead to a crisis or similar things, this price should be established below the natural market equilibrium. This is a type of price control and they usually apply to food and energy products when regular consumers cannot afford them.  

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.