A woman uses pills A as a method of birth control (or preventing pregnancy). The pills A stop the ovaries from releasing ovum into oviducts. Another woman uses pills B as a method of birth control. The pills B kill the sperms and prevent pregnancy.

(a) What do the pills A contain?

(b) What is the common name of pills A ?

(c) What do the pills B contain ?

(d) What is the common name of pills B ?

(e) What is the general name of these methods of birth control?