A 0.50kg mass hangs from a vertical spring of force constant 25N/m and is initially at its equilibrium position. The mass is then pulled downward an additional 0.080m and released from rest. If upward is taken as the positive y-direction, which of the following identifies the sign of the spring force and the sign of the net force on the mass immediately after release?
(a) Spring force positive; net force negative.
(b) Spring force negative; net force positive.
(c) Spring force positive; net force positive.
(d) Spring force negative; net force negative.