Which of the following creates the string of the numbers from 1 to 1000 most efficiently?
a. String s; for (int i = 1; i <= 1000; i++) s += i;
b. StringBuilder sb = new StringBuilder(10); for (int i = 1; i <= 1000; i++) (i);String s = new String(sb);
c. StringBuilder sb = new StringBuilder(3000); for (int i = 1; i <= 1000; i++) (i);String s = new String(sb);
d. All are equivalently efficient.