A
The femoral tunnel aperture
B
The posterior aspect of the proximal tibia
C
The medial femoral condyle articular margin
D
The anterior tibial tunnel aperture
Explanation:Correct Option: B. In a transtibial PCL reconstruction, the graft must make an acute, roughly 90-degree turn as it exits the posterior tibial tunnel aperture to enter the intra-articular joint space. This 'killer turn' can cause significant abrasion, cyclic stretching, and attenuation of the graft over time. (Ref: Berg, Arthroscopy, 1995)