In ΔABC, AD is the internal bisector of ∠A, meeting the side BC at D. If BD = 5 cm, BC = 7.5 cm, then AB : AC is

Answer: Option A

According to question,

By internal bisector property
$$\begin{array}{rl}& \frac{AB}{AC}=\frac{BD}{DC}\\ & \frac{AB}{AC}=\frac{5}{2.5}\\ & \frac{AB}{AC}=\frac{2}{1}\\ & \therefore AB:AC=2:1\end{array}$$