What should be added to $7\large\frac{4}{15}$ to get $8\large\frac{2}{5}$ ?

Question

( A ) $1\large\frac{2}{15}$
( B ) $3\large\frac{2}{15}$
( C ) $4\large\frac{2}{15}$
( D ) $2\large\frac{2}{15}$