Thinnest pa of the skull: (A) Lambdoid suture, (B) Temporal pa of bone, (C) Pterion, (D) Occiput
Answer is C. The anterior pa of the floor of the temporal fossa is crossed by an H shaped suture where four bones,frontal,parietal,greater wing of sphenoid and temporal adjoin each other.This area is termed the pterion. REF.B D Chaurasia's Human Anatomy VOL.3,Fouh edition