Q. A postman was returning to the post office which was in front of him to the North.

When the post office was 100 m away from him, he turned to the left and walked 50 m to deliver the last letter at CGO complex and moved another 50 m to meet his friend. Then he turned towards North and walked 100 m. How far is he from the post office?

(A) 150 m
(B) 100 m
(C) 50 m
(D) 75 m