[单选题]
An object is on a frictionless inclined plane. The planwz)mxs mse, 05:rw k6qe bqu tuw 9s.jg-3-r, dkis inclined at an angl 3-,r js-ubkugt q9dw.e of $30^{\circ}$ with the horizontal. What is the object's acceleration?
A. $0.50 \; g$
B. $0.56 \; g$
C. $0.87 \; g$
D. $1.0 \; g$
