[单选题]
An object is on a frictionles+ wx;ou 9o+gsw *xflf1s inclined plane. The plane is inclinh5s9 fyw h)k5zed at an angle ohfh z9y)5 5wskf $30^{\circ}$ with the horizontal. What is the object's acceleration?
A. $0.50 \; g$
B. $0.56 \; g$
C. $0.87 \; g$
D. $1.0 \; g$
