Consider the following statements:
1. Forced circulation is always used in high pressure power boilers.
2. Soot blowers are used for cleaning tube surfaces at regular intervals.
3. Electrostatic precipitator is used to remove fly ash from flue gases.
Which of these statements are correct?
(a) 1,2 and 3 (b) 2 and 3
(c)1 and 3 (d) 1 and 2