In What Ways Has the National Assembly Sought to Assert

In what ways has the National Assembly sought to assert itself?

A) It rejected a constitutional amendment proposed by President Obasanjo which would have allowed him additional terms in office.
B) It introduced impeachment proceedings against President Obasanjo.
C) It forced President Obasanjo to compromise on a federal budget.
D) It named Goodluck the Acting President when Yar'Adua became incapacitated.
E) All of the above are ways that the National Assembly sought to assert itself.