What did the 22nd amendment clarify?
who was the cause of this amendment?

The Twenty-Second Amendment, ratified in 1951, limits presidential tenure: no person may be elected President more than twice. This section clarifies original constitutional language on the status of a Vice President who succeeds to the presidency.

The Twenty-second Amendment was a reaction to Franklin D. Roosevelt's election to an unprecedented four terms as president, but presidential term limits had long been debated in American politics.                                          

i'd have to with d.

explanation:

i think you really need to revive you answer! : d