Non-overloadable operators in C#.NET — identify which among the list cannot be overloaded.

Introduction / Context:
C# restricts which operators can be overloaded. Knowing the non-overloadable ones is important.

Concept / Approach:
Operators like +, -, *, /, %, &, |, ^, ~, !, ++, --, true, false, and conversion operators (implicit/explicit) are overloadable. new and sizeof are not overloadable.

Why Other Options Are Wrong:
true and false are overloadable; ~ is overloadable; hence A and B are incorrect. D is incorrect because not all are overloadable. E is incorrect since true is overloadable.

Final Answer:
new and sizeof