Where will the hand of a clock stop if it (a) starts at 12 and makes `1/2` of a revolution, clockwise? (b) starte at 2 and makes `1/2` of a revolution, clockwise? (c) starts at 5 and makes `1/4` of a revolution, clockwise? (d) starts at 5 and makes `3/4` of a revolution, clockwise?