This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
Which of the following sites is not involved in a posterior cerebral aery infarct? 
Select and explain. 
A. Midbrain, B. Thalamus, C. Temporal lobe, D. Anterior Coex
D: Anterior Coex
Answer: D: Anterior Coex 
Explanation: In 75% of cases, both PCAs arise from the bifurcation of the basilar aery; in 20%, one has its origin from the ipsilateral internal carotid aery the posterior communicating aery; in 5%, both originate from the respective ipsilateral internal carotid aeries.Two clinical syndromes are commonly observed with occlusion of the PCAP1 syndrome: midbrain, subthalamic, and thalamic signs, which are due to disease of the proximal P1 segment of the PCA or its penetrating branches (thalamogeniculate, Percheron, and posterior choroidal aeries)P2 syndrome: coical temporal and occipital lobe signs, due to occlusion of the P2 segment distal to the junction of the PCA with the posterior communicating aery.(Ref: Harrison's 18/e p3286, 3287, 17/e p2525)