The following figure shows a right circular cylinder metal rod which is expanding as it is heated. After t seconds the radius of the rod is x cm and the length of the rod is 5x cm. The cross-sectional area of the rod is increasing at the constant rate of 0.032 cm²s-¹. Find dx/dt when the radius of the rod is 2 cm.

A 0.002546

B 0.003546

C 0.022546