Pls help I'm doing it but I need help Also, the subject is the leader in me, but there's no leader in me, so I just put geography.

When a lake, river or other aquatic  system  becomes  eutrophic, it can have serious negative effects on other organisms like fish, birds and even people.if an algal bloom is so bad that it causes wide-spread death  in  the  water, the organisms that die will all sink to the bottom and start to decompose.

answer is. c