**Core Concept**
The vaginal smear in a postmenopausal woman typically shows a decrease in the number of estrogen-sensitive cells, leading to a change in the cellular composition of the vaginal epithelium.

**Why the Correct Answer is Right**
The correct answer is associated with the atrophic changes that occur in the vagina due to the decrease in estrogen levels after menopause. The vaginal epithelium becomes thinner and less cellular, resulting in a predominance of **basal and parabasal cells**. These cells are less differentiated and are not as actively proliferating as the superficial cells found in premenopausal women. The reduction in estrogen levels leads to a decrease in the growth and differentiation of vaginal epithelial cells, resulting in atrophy.

**Why Each Wrong Option is Incorrect**
**Option A:** Atrophic cells are not the correct term for the cellular composition of the vaginal smear in an old lady. While atrophy is the correct term to describe the condition, the specific cells that are increased in number are basal and parabasal cells.

**Option C:** Superficial cells are typically seen in premenopausal women, not in old ladies. The decrease in estrogen levels leads to a reduction in the number of superficial cells.

**Option D:** Few intermediate cells seen is not the correct answer. Intermediate cells are typically seen in the vaginal epithelium of premenopausal women, and their number decreases with age.

**Clinical Pearl / High-Yield Fact**
In postmenopausal women, the vaginal epithelium becomes thinner and less cellular, leading to an increased risk of vaginal dryness, itching, and pain during intercourse. This is due to the decrease in estrogen levels and the resulting atrophy of the vaginal epithelium.

**Correct Answer: B. Basal and parabasal cells.**