Explanation:

A language is a set of strings over an alphabet. There are different types of languages depending on the rules that define them. Some of the commonly known language types are:

- Regular Languages: These languages are defined using regular expressions or finite automata. They are the simplest type of languages and can be recognized by deterministic or non-deterministic finite automata. Examples of regular languages are {0, 1}, {a, b}, etc.
- Context-Free Languages: These languages are defined using context-free grammars. They are more powerful than regular languages and can be recognized by push-down automata. Examples of context-free languages are {a^n b^n | n ≥ 0}, {a^n b^m c^m d^n | n, m ≥ 0}, etc.
- Context-Sensitive Languages: These languages are defined using context-sensitive grammars. They are more powerful than context-free languages and can be recognized by linear-bounded automata. Examples of context-sensitive languages are {a^n b^n c^n | n ≥ 0}, {ww^R | w ∈ {0, 1}*}, etc.
- Recursively Enumerable Languages: These languages are defined using Turing machines. They are the most powerful type of languages and can recognize any language that is computable. Examples of recursively enumerable languages are the set of all valid programs in a programming language, the set of all valid expressions in a mathematical language, etc.

False Statement:

The false statement is option 'D' which says that context-sensitive language is a subset of context-free language. This statement is not true because context-free languages are a subset of context-sensitive languages, not the other way around. This can be explained as follows:

- A context-sensitive grammar is a grammar in which the productions are of the form αAβ → αγβ, where A is a non-terminal and α, β, and γ are strings of terminals and non-terminals. This means that the replacement of A with γ is only allowed if the surrounding symbols are α and β.
- A context-free grammar is a grammar in which the productions are of the form A → γ, where A is a non-terminal and γ is a string of terminals and non-terminals. This means that the replacement of A with γ is allowed regardless of the surrounding symbols.
- Therefore, a context-free grammar is a special case of a context-sensitive grammar, where α and β are empty strings.

Conclusion:

In conclusion, option 'D' is the false statement because context-sensitive language is not a subset of context-free language, rather it is the other way around.