correct answerThe sizeof operator in C returns the size of:OptionsVariableData typeFunctionOperator

The sizeof operator in C returns the size of both a variable and a data type. It does not return the size of a function or an operator.

Here's how it works:

1. Variable: If you have a variable, for example, an integer variable, you can use sizeof to find out how much memory it takes up. For instance, int a; printf("%zu", sizeof a); will print out the size of a in bytes.

2. Data type: You can also use sizeof with a data type. For example, printf("%zu", sizeof(int)); will print out the size of an int in bytes.

Remember that the size returned by sizeof is dependent on the system you're running the code on. On most modern systems, an int is 4 bytes, but this isn't always the case.