The basic C compiler is 16 bit compiler, below are the size of it's data types
The size of short int is 2 bytes wide(16 bits).
The size of long int is 4 bytes wide(32 bits).

No, the carriage return tells the compiler to read the input from the buffer after ENTER key is pressed.

fmod(x,y) - Calculates x modulo y, the remainder of x/y.
This function is the same as the modulus operator. But fmod() performs floating point or long double divisions.

Yes, we can store either an ASCII character or a Unicode character in a char variable.