**Core Concept**
Cytomegalovirus (CMV) infection is a significant concern in transplant patients, particularly those undergoing solid organ transplantation. The risk of CMV infection is closely linked to the timing of the transplant and the recipient's immune status.

**Why the Correct Answer is Right**
The maximum risk of CMV infection occurs approximately 2-3 months post-transplantation, during a period known as the "peak phase." This is because the recipient's immune system is suppressed due to immunosuppressive therapy, making them more susceptible to viral reactivation or primary infection. CMV reactivation is triggered by the immunosuppressive regimen, particularly the use of calcineurin inhibitors and antilymphocyte globulin.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect, as CMV infection is not typically seen at 1-2 weeks post-transplantation, when the recipient's immune system is still being suppressed, but before the peak phase.
**Option B:** Incorrect, as CMV infection is not typically seen at 6-8 months post-transplantation, when the recipient's immune system is recovering and the risk of CMV infection decreases.
**Option C:** Incorrect, as CMV infection is not typically seen at 12-14 months post-transplantation, when the recipient's immune system is fully recovered and the risk of CMV infection is significantly reduced.

**Clinical Pearl / High-Yield Fact**
It's essential to note that CMV infection can occur at any time post-transplantation, but the peak phase between 2-3 months is the highest risk period. Regular monitoring of CMV antigenemia or DNA levels, along with prophylactic or preemptive therapy, can help mitigate the risk of CMV infection in transplant patients.

**Correct Answer: C. 2-3 months post-transplantation.**