**Core Concept**
The management of post coital bleeding in a 35-year-old lady involves identifying and addressing the underlying cause, which could be related to the reproductive system, including cervical, uterine, or ovarian pathology.

**Why the Correct Answer is Right**
Post coital bleeding is a symptom that requires thorough investigation to rule out cervical cancer, particularly in women with a high-risk human papillomavirus (HPV) infection. Colposcopy with biopsy is a crucial diagnostic step to evaluate the cervix for precancerous or cancerous changes. The correct answer involves a colposcopic examination to assess the cervix and take targeted biopsies.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not address the specific concern of post coital bleeding, which requires a focused evaluation of the reproductive system.
**Option B:** This option is incorrect because it implies a more general approach to managing post coital bleeding without considering the underlying pathology.
**Option C:** This option is incorrect because it does not accurately reflect the standard management approach for post coital bleeding in a 35-year-old lady.

**Clinical Pearl / High-Yield Fact**
A thorough colposcopic examination with biopsy is essential in the management of post coital bleeding to rule out cervical cancer, especially in high-risk HPV-infected women.

**Correct Answer: C. Colposcopy with biopsy.**