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Torque on Dipole in a Uniform Electric Field

When electric dipole is placed in uniform electric field, its two charges experience equal and opposite forces, which cancel each other and hence net force on electric dipole in uniform electric field is zero. However these forces are not collinear, so they give rise to some torque on the dipole. Since net force on electric dipole in uniform electric field is zero, so no work is done in moving the electric dipole in uniform electric field. However some work is done in rotating the dipole against the torque acting on it.

The dipole moment of a dipole in a uniform external field \[\overrightarrow{E}\] is \[\overrightarrow{P}\]. Then the toruqe \[\overrightarrow{\tau }\] acting on the dipole is

A) \[\overrightarrow{\tau }=\overrightarrow{P}\times \overrightarrow{E}\]

B) \[\overrightarrow{\tau }=\overrightarrow{P}\,\,.\,\,\overrightarrow{E}\]

C) \[\overrightarrow{\tau }=2\left( \overrightarrow{P}+\overrightarrow{E} \right)\]

D) \[\overrightarrow{\tau }=\left( \overrightarrow{P}+\overrightarrow{E} \right)\]