The correct option is C Increase president's power
ZANU-PF leader Robert Mugabe, elected prime minister in 1980, revised the constitution in 1987 to make himself president. Among the most radical of such amendments were; the abolition of seats reserved for white minority in parliament and the abolition of the office of the prime minister in 1987 and the creation of an executive presidency following a forced merger between Mugabe’s ZANU and the main opposition Patriotic Front (PF). Hence, Option A is correct. The rest of the clauses are contradictory to the 1987 amendment, hence, incorrect.