What was the Imperial Crisis, and what effect did it have on the fall of the Roman empire?

Ineed to have answers for numbers 2-4 reply to this question

The impeachment of president clinton by the u.s. house of representatives occurred with a. virtually all republicans supporting it, while virtually all democrats opposed it b. about two-thirds of republicans supporting it and about two-thirds of democrats opposing it c. half of all democrats and half of all republicans supporting it, while half of all democrats and half of all republicans opposed it d. virtually all democrats supporting it, while virtually all republicans opposed it

Which of the following is not a requirement to become a us representative (congressman/congresswoman)?