1).   Which of the following are unary operators in C?
1. !
2. sizeof
3. ~
4. &&

ANS: D - 1, 2, 3
An operation with only one operand is called unary operation.
Unary operators:
! Logical NOT operator.
~ bitwise NOT operator.
sizeof Size-of operator. && Logical AND is a logical operator. Therefore, 1, 2, 3 are unary operators.