Final answer:
The haplodiplontic life cycle, which includes alternation of generations, has both a haploid and a diploid multicellular stage and is found in plants. The correct answer is (c) Haplodiplontic.
Step-by-step explanation:
The type of life cycle that has both a haploid and a diploid multicellular stage is known as haplodiplontic. In this type of life cycle, organisms go through an alternation of generations, where they switch between two distinct forms: a multicellular haploid stage called the gametophyte and a multicellular diploid stage called the sporophyte. One example of organisms that follow this cycle is plants, wherein the gametophyte gives rise to gametes while the sporophyte generates spores that will develop into new gametophytes. The correct answer to which type of life cycle has both a haploid and a diploid multicellular stage is (c) Haplodiplontic.