Option (A) identifies them correctly.
During Meosis 2 daughter cells are formed from a single cell and the chromosomes are equally divided in both the cells.
So, Cell P had 60 chromosome, after miosis 2 daughter cells of each having 30 chromosomes formed, and again after Miosis of from each of those 2 those daughter cells, 2 more daughter cells are formed with equal naumber of chtomosome which equals 15.
The answer could be either B or D. Both are important for marine biology. I would have to say D is the best answer though!
Multi-cellular Heterotrophs
Animals have more than one cell and can't produce their own food