The velocity of light in glass whose refractive index with respect to air is $1.5$ is $2 \times 10^{8} \mathrm{~m} / \mathrm{s}$. In a certain liquid, the velocity of light is found to be $2.5 \times 10^{8} \mathrm{~m} / \mathrm{s}$. What is the refractive index of the liquid with respect to air?
(A) $1.44$
(B) $0.80$
(C) $1.20$
(D) $0.64$