In an assignment statement a=b; which of the following statement is true?

1.3 In an assignment statement a=b; which of the following statement is true?
A) The variable a and the variable b are same.
B) The value of b is assigned to variable a but if b changes later, it will not effect the value of variable a.
C) The value of b is assigned to variable a but if b changes later, it will effect the value of variable a.
D) The value of variable a is assigned to variable b, and the value of variable b is assigned to variable a.