Which of the following types of algae shows a distinct alternation of generations? .

I think you forgot to give the options along with the question. I am answering the question based on my knowledge and research. "Chlorophytes" is the one type of algae that shows a distinct alternation of generations. I hope that this is the answer that you were looking for and it has actually come to your help.

They formed the oceans.  as they melted water was formed and the water made the oceans