Charges are placed on the vertices of a square as shown. Let $\overrightarrow{E}$ be the electric field and $V$ the potential at the centre. If the charges on A and B are interchanged with those on D and C respectively, then : <br>

Question

( A ) $\overrightarrow{E}$ and V remains unchanged
( B ) $\overrightarrow{E}$ remains unchanges, V changed
( C ) $\overrightarrow{E}$ changes, V remains unchanged
( D ) both $\overrightarrow{E}$ and V change