**Core Concept**
Vacuum-Assisted Closure (VAC) therapy is a topical wound treatment that utilizes a negative pressure environment to promote wound healing. This involves the application of a controlled, sub-atmospheric pressure to enhance blood flow, reduce edema, and promote granulation tissue formation.

**Why the Correct Answer is Right**
The application of negative pressure in VAC therapy indeed promotes a decrease in bacterial counts and an increase in cell proliferation in the wound. This is achieved through several mechanisms: the removal of excess fluid and debris from the wound bed, the promotion of angiogenesis (formation of new blood vessels), and the stimulation of collagen synthesis. The increased oxygenation of the wound tissue also contributes to the enhanced cellular activity. The reduction in bacterial counts is particularly important, as it helps to prevent wound infections and promote a clean environment for healing.

**Why Each Wrong Option is Incorrect**
**Option B:** Continuous pressure of +125 mmHg is actually not applied in VAC therapy; instead, a controlled negative pressure is applied, typically ranging from -75 to -125 mmHg.

**Option C:** VAC therapy actually reduces interstitial edema, thereby decreasing blood flow to the wound rather than increasing it. The reduction in edema helps to promote a clean and stable wound environment.

**Option D:** VAC therapy is generally contraindicated over malignancies in the wound, as the negative pressure may dislodge and spread cancer cells. This is a critical consideration in the management of wounds with suspected malignancy.

**Clinical Pearl / High-Yield Fact**
When using VAC therapy, it's essential to monitor the wound regularly for signs of infection, such as increased redness, swelling, or purulent discharge. This helps to prevent complications and ensure the optimal healing environment.

**✓ Correct Answer:** A. Due to negative pressure , bacterial counts decrease and cell proliferation increases in the wound.