**Core Concept:**
The provided question is describing a set of clinical signs and laboratory findings associated with a specific condition. We are looking for the correct diagnosis among the given options. The core concept involves understanding endocrinological disorders, particularly the Polycystic Ovary Syndrome (PCOS) and its associated features.

**Why the Correct Answer is Right:**
PCOS is a hormonal disorder affecting women of reproductive age. The key feature of PCOS is the presence of multiple small cysts in the ovaries, which leads to irregular menstrual cycles, hyperandrogenism, and insulin resistance. The elevated blood glucose level is a result of insulin resistance, as the body tries to compensate for it by producing more insulin. Moreover, the large jaw, hands, and feet are indicative of acanthosis nigricans, a skin condition that can be associated with insulin resistance due to PCOS.

**Why Each Wrong Option is Incorrect:**
A. Elevated blood glucose level alone is not sufficient to diagnose PCOS, as it could be indicative of other conditions like diabetes or hypothyroidism.
B. Large jaw and hands/feet are not exclusive to PCOS, and can be seen in other conditions like acromegaly or Cushing's syndrome.
C. Normal height is not contradictory to the diagnosis of PCOS, as height variations are not a defining feature of this condition.
D. Insulin resistance is a feature of PCOS, not its sole diagnosis.

**Clinical Pearl:**
Acanthosis nigricans should prompt further evaluation for insulin resistance and PCOS in women of reproductive age, particularly when accompanied by other symptoms like irregular periods and hirsutism. This clinical pearl emphasizes the importance of considering endocrinological disorders when evaluating patients with specific clinical features.

**Correct Answer:**
. D. Insulin resistance is a feature of PCOS, not its sole diagnosis.