A local post office is to send M telegrams which are distributed at random over N communication channels, (N > M). Each telegram is sent over any channel with equal probability. Chance that not more than one telegram will be sent over each channel is

• A

  $\frac{{ }^{\mathrm{N}}{\mathrm{C}}_{\mathrm{M}}\times \mathrm{N}!}{{\mathrm{M}}^{\mathrm{N}}}$

• B

  $\frac{{ }^{\mathrm{N}}{\mathrm{C}}_{\mathrm{M}}\times \mathrm{M}!}{{\mathrm{N}}^{\mathrm{M}}}$

• C

  $1-\frac{{ }^{\mathrm{N}}{\mathrm{C}}_{\mathrm{M}}\times \mathrm{M}!}{{\mathrm{M}}^{\mathrm{N}}}$

• D

  $1-\frac{{ }^{\mathrm{N}}{\mathrm{C}}_{\mathrm{M}}\times \mathrm{N}!}{{\mathrm{N}}^{\mathrm{M}}}$