Which term describes hot or cold mixture of water and rock fragments (can be any size) flowing down the slopes of a volcano and (or) river valleys. They are essentially volcanic mudflows/debris flows.

Don't depend on this but logically i think c

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.

Canada and