Pole P is 13 Km towards the east of pole Q. Siddharth , starts from pole Q, travels 8Km towards West and takes a right turn. After taking the right turn, he travels 5Km and reaches pole B .From pole B, Siddharth takes a right turn again, travel 21Km aand reaches pole C . How far and towards which direction must the Siddharth travel to reach pole P ?
A. 5 km towards south
B. 5 km towards west
C. 21 km towards south
D. 13 km towards south