**Core Concept**
A clean incised wound is a type of traumatic wound characterized by a sharp, clean cut in the skin, typically caused by a knife or other sharp object. The healing of such wounds involves the coordinated effort of various cell types and tissue components.

**Why the Correct Answer is Right**
Clean incised wounds typically heal by primary intention, which means that the wound edges are approximated and the wound heals with minimal scarring. This occurs because the wound edges are clean and free of debris, allowing for rapid closure of the wound through the process of collagen deposition and tissue repair. The process of healing by primary intention involves the activation of platelets, which release growth factors that stimulate the migration and proliferation of fibroblasts, leading to the deposition of collagen and the formation of a strong scar.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because clean incised wounds do not typically heal by secondary intention, which involves the formation of a granulating bed and the subsequent contraction of the wound.
**Option B:** This option is incorrect because clean incised wounds do not typically involve the formation of a keloid, which is a type of raised scar that occurs in response to injury.
**Option C:** This option is incorrect because clean incised wounds do not typically heal by tertiary intention, which is not a recognized mechanism of wound healing.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the healing of a wound can be affected by various factors, including the cleanliness of the wound, the presence of infection, and the overall health of the patient.

**Correct Answer: D. Primary intention**