**Core Concept**
Hyperacute rejection is a severe and rapid form of rejection that occurs immediately or within minutes to hours after transplantation. It is primarily caused by pre-existing antibodies against the donor organ's antigens, leading to activation of the complement system and subsequent damage to the graft.

**Why the Correct Answer is Right**
Hyperacute rejection is mediated by pre-formed antibodies against the donor organ's human leukocyte antigens (HLA) or ABO blood group antigens. These antibodies can bind to the donor organ's endothelial cells, triggering the activation of the complement system, which causes inflammation, coagulation, and ultimately, graft failure. The activation of the complement system leads to the formation of membrane attack complexes, which create pores in the cell membrane, causing cell lysis and tissue damage.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because hyperacute rejection is not primarily caused by cellular immunity, such as T-cell activation. While T-cells can contribute to acute rejection, hyperacute rejection is mediated by pre-existing antibodies.
**Option B:** This option is incorrect because graft-versus-host disease (GVHD) is a complication of allogeneic bone marrow transplantation, where the donor's immune cells attack the recipient's tissues. It is not directly related to hyperacute rejection.
**Option C:** This option is incorrect because chronic rejection is a slow and progressive form of rejection that occurs months to years after transplantation, often due to chronic inflammation and immune activation.

**Clinical Pearl / High-Yield Fact**
It is essential to perform thorough cross-matching between the donor and recipient before transplantation to minimize the risk of hyperacute rejection. This includes testing for ABO blood group compatibility and HLA typing to identify potential antibody incompatibilities.

**Correct Answer:** D. (Assuming D was the correct answer, if not, please provide the correct answer)