The right answer is C. Diploid and haploid phases alternate.
The alternation meiosis-fertilization introduces a cycle in the development of an organism characterized by an alternation of chromosomal phases, haplophase and diplophase.
In plants, alternating chromosome phases are superimposed alternating biological forms or generations. Each species typically lives and successively under two distinct biological forms, one haploid corresponding to haplophase, the other diploid corresponding to the diplophase.
