Running speeds of steam turbine can be brought down to practical limits by which of the following method (s)?
1. By using heavy flywheel.
2. By using a quick response governor.
3. By compounding.
4. By reducing fuel feed the furnace
(a) 3 alone (b) 1,2,3 and 4
(c) 1,2 and 4 (d)2 and 3