Crossing Over Is One of the Most Important Events in Meiosis

Crossing over is one of the most important events in meiosis because

A) homologous chromatids must be separated into different daughter cells.
B) homologous chromosomes must be separated into different daughter cells.
C) the number of chromosomes allotted to each daughter cell must be halved.
D) it produces new arrays of alleles on chromosomes.
E) All of the choices are correct.