'x' is same as "x"

length of the string "x" is two

Unless otherwise specified, the first name in an enum has the value 1

None of the above

finds the hypotenuse of a triangle with sides a + 2 and b + 3

finds the square root of (a + 2)2 + (b + 3)2

is invalid

finds the square root of 3 * a + 4 * b + 5

cannot be beyond the file in which it is defined

may be part of a file

is the entire program

excludes string of characters within double quotes

The opening parenthesis should immediately follow the macro name

There should be at least one blank between the macro name and the opening parenthesis

There should be only one blank between the macro name and the opening parenthesis

All the above comments are correct

a C compiler

an inter-active debugger

a C interpreter

a tool for analysing a C program