In Ferns, Both the Gametophyte and Sporophyte Are Physiologically Capable

In ferns, both the gametophyte and sporophyte are physiologically capable of surviving on their own. Which of the following are reasonable hypotheses for why vascular tissues are present only in the sporophyte generation?

A) There is no advantage for the gametophyte to grow tall, because gametes must be produced near the ground where the water needed for their free-swimming sperm is most likely to be found.
B) Vascular tissues are incompatible with desiccation tolerance.
C) Haploid organisms are incapable of developing vascular tissues, such as xylem and phloem.
D) There is no advantage for the gametophyte to grow tall, because fern gametophytes typically produce only male or female gametes at any one time.