Which of the following is immutable data type in Python?

Correct answer: Tuple

Explanation:

• What immutable means: an immutable object cannot be changed after it is created.

• Why tuple is immutable: you cannot assign to a tuple element or add/remove elements. For example, trying to do t[0] = value will raise a TypeError.

• Contrast with mutable types: list, set, and dictionary can be modified after creation using operations like append(), add(), pop(), update(), or assignment to indices/keys.

• Immutable alternatives: frozenset is an immutable set; strings and numeric types are also immutable.

• When to use tuple: for fixed collections of items, for grouping values that should not change, and when you need a hashable sequence (e.g., as a dictionary key).