Which of the following adds 42 to the element at the fifth physical spot?

int [ ] x = {12, 13, 14, 15, 16, 17, 18, 19};

a. x[5] += 42;

b. x[4] += 42;

c. x[5 + 42];

d. x = 42 + 5;

e. none of the above