In the figure, the blocks have unequal masses m1 and m2 (m1 > m2). m1 has a downward acceleration a. The pulley P has a radius r, and some mass. The string does not slip on the pulley.

(a) The two sections of the string have unequal tensions.
(b) The two blocks have accelerations of equal magnitude.
(c) The angular acceleration of P is a/r.
(d) a < (m1 - m2 / m1 + m2) g