If $4P(A)= 6, P(B) = 10, P(A ∩ B)= 1,$ then $P\left(\frac{B}{A}\right)=$

$\frac{2}{5}$ $\frac{3}{5}$ $\frac{7}{10}$ $\frac{19}{60}$

$\frac{2}{5}$

$P\left(\frac{B}{A}\right) = \frac{P(A∩B)}{P(A)}=\frac{(1/10)}{(1/4)}=\frac{2}{5}.$