**Core Concept**
The patient's presentation is suggestive of a chronic granulomatous disease, likely tuberculosis (TB), given the presence of bilateral nodular lesions on the shins (tuberculids), bi-lateral hilar lymphadenopathy, and a positive Mantoux test. The skin biopsy would reveal a specific histopathological feature characteristic of TB.

**Why the Correct Answer is Right**
The Mantoux test is a screening tool for latent TB infection, and an induration of 5 mm or more is considered a positive result in individuals with a high risk of TB exposure or in regions with a high TB prevalence. The presence of bilateral hilar lymphadenopathy on chest X-ray is a classic radiographic finding in pulmonary TB. The skin biopsy would likely show granulomatous inflammation, characterized by the presence of epithelioid cells, Langhans giant cells, and a surrounding lymphocytic infiltrate. This histological finding is a hallmark of TB.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately describe the histopathological features of TB. While a skin biopsy might show some inflammatory changes, the specific findings of granulomatous inflammation are not characteristic of this condition.
**Option B:** This option is incorrect as it is not a specific histopathological feature of TB. A skin biopsy might show some changes in the skin, but the specific findings of granulomatous inflammation are not characteristic of this condition.
**Option C:** This option is incorrect as it does not accurately describe the histopathological features of TB. While a skin biopsy might show some inflammatory changes, the specific findings of granulomatous inflammation are not characteristic of this condition.

**Clinical Pearl / High-Yield Fact**
A Mantoux test induration of 5 mm or more in a young lady with bilateral nodular lesions on shins and bi-lateral hilar lymphadenopathy on chest X-ray should raise a high suspicion for TB. A skin biopsy would likely show granulomatous inflammation, which is a hallmark of TB.

**Correct Answer:** C.