Suppose that i and j are both of type int. What is the value of j after each of the following statements is executed?

a. for (i = 0, j = 0; i < 10; i++) j += i;

b. for (i = 0, j = 1; i < 10; i++) j += j;

c. for (j = 0; j < 10; j++) j += j;

d. for (i = 0, j = 0; i < 10; i++) j += j++;