Which of the following statements regarding diminishing marginal returns is most accurate（）

A. As the quantity produced rises, costs begin to rise at a decreasing rate.

B. As the quantity produced falls, costs begin to rise at a decreasing rate.

C. As the quantity produced rises, costs begin to rise at an increasing rate.

血虚导致妇科疾病下列哪项不常见：

A．月经过少

B．闭经

C．痛经

D．癥瘕

E．产后血晕