C#.NET — Identify correct statements about functions (recursion, nesting, returns, and nested calls). Which of the following statements are correct about functions used in C#.NET? Function definitions cannot be nested. Functions can be called recursively. If we do not return a value from a function then a value -1 gets returned. To return the control from middle of a function, the keyword "exit function" should be used. Function calls can be nested.

Introduction / Context:
This conceptual question checks your knowledge of basic method (function) behavior in C#.NET: recursion, whether you can nest function definitions, what happens if a function omits a return value, how to return from the middle of a function, and whether function calls can be nested in expressions.

Given Data / Assumptions:

• Five statements about C# functions are provided.
• We consider conventional C# practice used in most beginner–intermediate curricula and certification-style questions.

Concept / Approach:
Evaluate each statement against core C# rules: recursion is allowed; functions are defined at type scope (traditional teaching says no nested function definitions); there is no implicit -1 return; and C# uses the keyword return to exit a method early. Function calls can indeed be nested, as expressions can contain other calls.

Step-by-Step Solution:

Verification / Alternative check:
Compile small examples: a) recursion (factorial); b) nested calls like Math.Max(Math.Abs(-5), 3); c) attempt to omit a return in a non-void method will fail with a compiler error; d) “exit function” keyword is not recognized by C#; e) standard method declarations exist at type scope in typical codebases.

Why Other Options Are Wrong:

• B includes 3, which is false.
• C includes 3 and omits 5; incorrect.
• D includes 4, which is false.
• E is wrong because a correct set exists (1, 2, 5).

Common Pitfalls:
Confusing C# with VB (using “exit function”), assuming a magic default return value, or thinking nested calls are disallowed.

Final Answer:
1, 2, 5