A $400$ V $,$ single$-$phase synchronous motor gives a net output mechanical power of $7\mathrm{.}35$ kW and operates at $0\mathrm{.}92$ pf lagging. Its effective resistance is $0\mathrm{.}7$ ohm $.$ If the iron and mechanical losses are $550$ W and excitation losses are $750$ W $.$ Calculate the armature current.

A$.29\mathrm{.}52$ A

B$.21\mathrm{.}84$ A

C$.28\mathrm{.}48$ A

D$.22\mathrm{.}42$ A