Two block `A` and `B` of masses `3m` and `m` respectively are connected by a massless and nextensible string. The whole system is suspended by a massless spring as shown in figure. The magnitudes of acceleration of `A` and `B` immediately after the string is cut, are resectively
A. `g,(g)/(3)`
B. `(g)/(3),g`
C. g,g
D. `(g)/(3),(g)/(3)`