In the following question, out of the four alternatives, select the single word which is the best substitute for the phrase: "Man behaving more like a woman than as a man".

Introduction / Context:
This vocabulary question asks you to find the most accurate one-word substitute for the phrase "Man behaving more like a woman than as a man". Such questions test your knowledge of descriptive adjectives used in English to talk about behaviour, personality, or appearance. While some of these words can be sensitive, they still appear in exam syllabi and classical texts, so you must know their meanings.

Given Data / Assumptions:
- Phrase: Man behaving more like a woman than as a man.
- Options:
- Biped.
- Effeminate.
- Gregarious.
- Inalienable.
- The phrase refers to a man whose mannerisms, behaviour, or style are considered typically feminine in a traditional sense.

Concept / Approach:
The word effeminate is traditionally used to describe a man who shows traits, behaviour, or appearance that are culturally associated with women, such as softness, delicacy, or a particular style of speech and movement. While modern discussions may avoid this word for social reasons, exams still test it as a dictionary term. The other options refer to completely different ideas: a biped is a two-legged creature, gregarious means sociable, and inalienable refers to rights that cannot be taken away.

Step-by-Step Solution:
Step 1: Interpret the phrase carefully. It does not describe walking on two legs, being friendly, or having permanent rights; it focuses on gender-related behaviour.Step 2: Check "Biped". This simply means a creature that walks on two feet. It applies to all humans and many animals, not specifically to a man behaving like a woman.Step 3: Check "Effeminate". This adjective describes a man who is considered to have characteristics traditionally attributed to women, which matches the phrase.Step 4: Check "Gregarious". This means sociable, fond of company, and does not carry any gender-related meaning.Step 5: Check "Inalienable". This word refers to rights or properties that cannot be taken away or transferred, unrelated to behaviour.Step 6: Therefore, effeminate is the only option that fits the phrase.

Verification / Alternative check:
In many dictionaries, effeminate is defined as "having or showing characteristics regarded as typical of a woman; unmanly". Example usage: "His effeminate style of dressing was criticized by traditionalists." This mirrors the exam phrase very closely. Substituting biped, gregarious, or inalienable into that kind of sentence would make it meaningless or change the subject completely.

Why Other Options Are Wrong:
- Biped: focuses only on the physical fact of walking on two legs; all humans are bipeds by default.
- Gregarious: describes someone who likes to be with other people; it does not say anything about feminine or masculine traits.
- Inalienable: relates to rights or properties and is a technical term in law and philosophy.

Common Pitfalls:
Some learners are tempted to select complex-sounding words such as inalienable or gregarious simply because they seem advanced. However, one-word substitution questions demand an exact match to the phrase, not just a difficult word. Always focus on the central idea in the phrase. Here, the key is "behaving more like a woman", which directs you straight to effeminate if you know its definition.

Final Answer:
The correct one-word substitute for "Man behaving more like a woman than as a man" is Effeminate.