By which relation speed of piston can be calculated inside cylinder block?(L-Length of stoke, D-Diameter, N-speed of engine)

By which relation speed of piston can be calculated inside cylinder bl

1.	By which relation speed of piston can be calculated inside cylinder block? (L-Length of stoke, D-Diameter, N-speed of engine)
A.	2LDN
B.	2LN
C.	2 LD
D.	2 L
Answer» C. 2 LD