Consider the following statements:

In petrol engine mechanism, the piston is at its dead centre position when piston 1). acceleration is zero 2). acceleration is maximum 3). velocity is zero 4). velocity is infinity.

Which of these statements are correct?

(a) 1 and 4

(b) 1 and 3

(c) 2 and 3

(d) 2 and 4 .