A lossless transmission line with characteristic impedance $$Z_0 = 50$$ ohm is 30 m long and operates at 2 MHz. Theline is shorted at the load, if the phase velocity = 0.6 times the velocity of light, the input impedance of the line is:

A

$$75 \angle{90^\circ}$$ ohm

B

$$\frac{50}{\sqrt{3}} \angle{180^\circ}$$ ohm

C

$$\frac{100}{\sqrt{2}} \angle{180^\circ}$$ ohm

D

$$\frac{75}{\sqrt{2}} \angle{270^\circ}$$ ohm