Geography grades 6 and 7 by myrl shireman page 40-41

Ithink the answer to that would be b):

Icant awnser the qustion bc u have the planets not listed

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.