Which of the following descriptions of embryo development after fertilization is incorrect?

A、The gemellarypregnancy that two eggs are fertilized separately is called the dizygotic twin.;
B、The gemellary pregnancywhich formed by the division of a zygote is called the monozygotic twin.;
C、If the monozygotic twins failed to separate or couldn’t separate thoroughly during the early development of pregnancy, there would be a conjoined child.;
D、One sperm splits into two and then fertilizes with two eggs which is called dizygotic twin.