A thematic map would most likely be useful for finding information about the A. Chemical composition of the soil

B. Elevation of dense rain clouds

C. Ways people interact with environment

D. Lesser known features of the ocean

Is there a picture of the diagram?

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.

Iwould say the answer is d

Ithink its d.stratum