Answer:
The correct answer would be c. alteration of generation.
It refers to the reproduction pattern usually observed in lower plants in which their life cycle alternate between diploid (sporophyte) and haploid (gametophyte) stages.
The sporophyte represents the diploid stage which produces haploid spores through the process of meiosis.
The spored lead to the formation of haploid gametophyte which produces male and female gametes through mitotic division.
The fusion of the gametes leads to the production of a diploid zygote which matures into a diploid sporophyte.
Thus, they alternate between haploid and diploid stages.
