The animal group classified as being the most critically endangered is the?

The choices can be found elsewhere and as follows:

birds. 
amphibians. 
fish. 
reptiles. 

I think the correct answer is the third option. The animal group classified as being the most critically endangered is the fish. This animal group is endangered since they are being caught everyday and are being consumed by many living organisms including humans.

The investiture controversy began as a power struggle between pope gregory vii (1072–85) and henry iv, holy roman emperor (1056–1106).[2] a brief but significant struggle over investiture also occurred between henry i of england and pope paschal ii in the years 1103 to 1107, and the issue played a minor role in the struggles between church and state in france, as well.by undercutting the imperial power established by the salian emperors, the controversy led to nearly 50 years of civil war in germany, and the triumph of the great dukes and abbots. imperial power was finally re-established under the hohenstaufen dynasty. historian norman cantor:

How am i supposed to know your lecture