Two Objects of Differing Masses $\left( m _ { a } , m _ { b } \right)$

Two objects of differing masses $\left( m _ { a } , m _ { b } \right)$ are released from the top of two frictionless inclines having the same height. Mass $m _ { a }$ is on an incline that makes an angle of $15 ^ { \circ }$ with the horizontal; mass $m _ { b }$ is on an incline that makes an angle of $75 ^ { \circ }$ with the horizontal. At the bottom, the mass that has the greater speed is

A) $m _ { a }$
B) $m _ { b }$
C) Both masses have the same speed.
D) This cannot be determined unless both masses ( $m _ { a } , m _ { b }$ ) are known.