English Vocabulary — Choose the best synonym (same meaning). Target word: cage

Introduction / Context:
A “cage” is a structure that confines animals or birds—typically an enclosure made with bars or mesh. When selecting a synonym, prefer a word that captures the idea of a space designed to contain or confine, not a user or location associated with it.

Given Data / Assumptions:

• Target: cage.
• Options: enclosure, prisoner, animal, zoo, penalty.
• We focus on the physical object/space meaning.

Concept / Approach:
“Enclosure” denotes a space that is closed in or fenced off; in many contexts, a cage is a specific type of enclosure. Therefore it is the closest available synonym among the choices.

Step-by-Step Solution:

Verification / Alternative check:
Substitution: “Place the bird back in its cage.” → “Place the bird back in its enclosure.” Meaning is preserved, though “enclosure” is a bit broader than “cage.” It remains the closest synonym among the options.

Why Other Options Are Wrong:

• prisoner: a person/animal that is confined, not the container.
• animal: occupant, not container.
• zoo: collection of many habitats/enclosures; too broad.
• penalty: unrelated to containment structures.

Common Pitfalls:
Picking an associated noun (occupant/place) rather than the container itself.

Final Answer:
enclosure