The time constant of a unity gain, first order plus time delay process is 5 min. If the phase lag at a frequency of 0.2 rad/min is 60°, then the dead time (in minutes) is

A. $$\frac{{5\pi }}{{12}}$$

B. $$\frac{\pi }{6}$$

C. $$\frac{\pi }{{12}}$$

D. $$\frac{\pi }{3}$$

Answer: Option A