In Pines, the Mature Male Gametophyte Consists Of

In pines, the mature male gametophyte consists of:

A) one tube cell and one generative cell.
B) one tube cell, one sterile cell, and one spermatogenous cell.
C) two prothallial cells, one tube cell, and one generative cell.
D) two prothallial cells, one tube cell, one sterile cell, and one spermatogenous cell.
E) two prothallial cells, one tube cell, one sterile cell, and two sperm.