The variable that does not change the value during execution of program is. . . . . . . .

The correct answer is C. constant.

A constant is a variable whose value cannot be changed during the execution of a program. It is declared using the keyword const. For example,

const int x = 10;

The value of x cannot be changed after it is declared.

A numeric variable is a variable that can store a number. It is declared using the keyword int, float, or double. For example,

int x = 10;
float y = 3.14;
double z = 6.02214179e23;

A string variable is a variable that can store a sequence of characters. It is declared using the keyword string. For example,

string s = "Hello, world!";

None of the options A, B, and D are correct.