On which of the following parts of the human body does hair normally not grow?

Introduction / Context:
Human skin is covered with hair follicles almost everywhere, but there are a few special regions where hair does not normally grow. Questions about these regions appear in basic biology, human anatomy, and general science sections. This question asks which specific parts of the human body are normally hairless. Understanding this helps reinforce knowledge of how the skin and its appendages vary across different body regions.

Given Data / Assumptions:

• The body parts listed are sole of the feet, palms, and lips.
• The question is about normal conditions in healthy individuals.
• We focus on visible hair growth and typical anatomical patterns, not rare medical anomalies.

Concept / Approach:
Most of the human body has hair follicles that produce fine or coarse hair. However, certain specialized skin areas are called glabrous skin and are naturally hairless. These include the palms of the hands, soles of the feet, and parts of the lips (especially the vermilion border). These areas contain sweat glands and are adapted for functions such as gripping, walking, and forming a seal for speech and eating, rather than for hair growth. Therefore, all three of the listed regions are normally free from hair follicles that produce typical body hair.

Step-by-Step Solution:
1. Consider the sole of the feet. This area is normally hairless and specialized for weight bearing and walking.2. Consider the palms of the hands. These surfaces are smooth, hair free, and adapted for gripping and fine motor tasks.3. Consider the lips. The visible red portion has a different type of skin and is usually free from normal body hair.4. All three areas are classic examples of glabrous skin, which lacks hair follicles.5. Therefore, the correct answer that includes all these regions is “All of the above.”

Verification / Alternative check:
Standard anatomy texts describe glabrous skin on the palms and soles as being thicker and more richly innervated, with no hair follicles and many sweat glands. The lips also have a specialized surface that transitions from facial skin to the moist mucosa inside the mouth. Everyday observation confirms that, under normal circumstances, people do not have hair growing on the palms or soles, and the outer lips remain hairless. These facts clearly support the conclusion that all options given are regions where hair normally does not grow.

Why Other Options Are Wrong:
Option A, “Sole of the feet,” is partially correct but incomplete because it excludes the other hairless regions listed. Option B, “Palms,” is also incomplete for the same reason. Option C, “Lips,” again describes one hairless region but misses the others. Since the question is asking which of the listed parts do not have hair, and all three do not, the only fully correct choice is Option D, “All of the above.”

Common Pitfalls:
Some learners might overthink the question and imagine rare conditions where hair might appear in unusual places, but exam questions are based on normal anatomy. Another pitfall is to remember the palms and soles but forget the lips, or to think about fine facial hair and mistakenly assume the lips must also grow hair. To avoid confusion, remember that the most prominent hairless skin regions in humans are the palms, soles, and the outer lip surface, all of which are referred to as glabrous skin areas.

Final Answer:
Hair normally does not grow on the sole of the feet, palms, and lips, so the correct option is “All of the above.”