What will be the value of sin10° - 4/3 sin310°?

Answer: Option B

$$\begin{array}{rl}& \sin 10-\frac{4}{3}{\sin }^{3}10\\ & =\frac{3\sin 10-4{\sin }^{3}10}{3}\\ & =\frac{1}{3}\sin 3\times 10^{\circ }\left[\because \sin A=3\sin A-4{\sin }^{3}A\right]\\ & =\frac{1}{3}\times \frac{1}{2}\\ & =\frac{1}{6}\end{array}$$