(A) : The soldiers marching on a suspended bridge are advised to break their step.
(R) : Frequency of marching steps may match with the natural frequency of oscillations of bridge.

Options

A. Both 'A' and 'R' are ture and 'R' is the correct explanation of 'A'
B. Both 'A' and 'R' are true and 'R' is not the correct explanation of 'A'
C. A' is true and 'R' is false
D. A' is false and 'R' is true

Answer

A