Which of the following statements is true of test marketing?
选项：

A: The amount of test marketing needed remains constant for each new product.
B: When the costs of developing and introducing the product are low, the company will have to do significant test marketing.
C: Test marketing is seldom done on products that are risky.
D: Test marketing is seldom done when management is not sure of the product or its marketing program.
E: Test marketing costs can be high, and it takes time that may allow competitors to gain advantages.