Which of the following is a valid SQL statement?

a. SELECT TRUNC (ROUND (125.38, 1), 0) FROM dual;

b. SELECT ROUND (TRUNC (125.38, 0)

FROM dual;

c. SELECT LTRIM(LPAD (state, 5, ' '), 4, -3, "*")

FROM dual;

d. SELECT SUBSTR (ROUND (14.87, 2, 1), -4, 1)

FROM dual;