**Core Concept**
The Bisgaard method is a surgical approach used to treat venous ulcers. It involves the resection of the incompetent saphenofemoral junction, which is a common site for venous reflux. This procedure aims to eliminate the source of venous hypertension and promote healing of the ulcer.

**Why the Correct Answer is Right**
The Bisgaard method involves the resection of the saphenofemoral junction, which is a critical step in treating venous ulcers. This procedure is typically performed under general anesthesia and involves the removal of the incompetent vein. The goal of this surgery is to eliminate the source of venous reflux, which can help to reduce venous hypertension and promote healing of the ulcer. The Bisgaard method is often performed in conjunction with other treatments, such as compression stockings and wound care.

**Why Each Wrong Option is Incorrect**
**Option A:** Hilton's method is not a recognized method for treating venous ulcers. It is possible that this option is a distractor or a reference to a different medical concept.
**Option B:** Trivex method is not a valid treatment for venous ulcers. This option may be a distractor or a reference to a different medical device or technology.
**Option D:** Tessari method is not a recognized method for treating venous ulcers. It is possible that this option is a distractor or a reference to a different medical concept.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the Bisgaard method is just one of several surgical approaches used to treat venous ulcers. Other methods, such as the Linton procedure and the stripping of the great saphenous vein, may also be used in certain cases. A thorough understanding of these different surgical approaches is crucial for treating patients with venous ulcers.

✓ Correct Answer: C. Bisgaard method