Final answer:
The plants involved in this scenario are bryophytes, and they have formed haploid zygotes.
Step-by-step explanation:
The correct statement describing the plants involved is D. The plants are bryophytes, and they have formed haploid zygotes.
In certain plants, such as bryophytes, sperm are released and swim through standing water to find the archegonia. The sperm and egg meet in the archegonium, where fertilization takes place and a diploid zygote is formed. However, in bryophytes, the zygote immediately undergoes meiosis, resulting in a haploid sporophyte.
Therefore, the plants involved in this scenario are bryophytes, and they have formed haploid zygotes.