This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
True about synol membrane of knee joint is 
Select and explain. 
A. Invaginated posteriorly by cruciate ligament, B. Extension into prepatellar bursa, C. Covers inferior surface of both menisci, D. Extension into infrapatellar bursa
A: Invaginated posteriorly by cruciate ligament
Answer: A: Invaginated posteriorly by cruciate ligament 
Explanation: A. i.e. Invaginated posteriorly by cruciate ligament Synol membrane reflects from posterior aspect of joint on to the cruciate ligaments (ant. & post.) making them extrasynol structuresQFour bursae communicate with the synol cavity of knee joint - suprapatellar bursa, popliteal bursa, anserine (semimembranosus) bursa & gastrocnemius bursa.QCruciate ligaments are intraicular (or intracapsular) but extra synolQ structures.Menisci are intraicular (capsular) & intrasynol structures but its surface has no synol coveringQ. It's upper surface are in contact with femoral condyle & lower surface with tibial condyle.