ABCD is a parallelogram, with AC, BD as diagonals, then $\overrightarrow{AC} - \overrightarrow{BD}$ is equal to :

Question

( A ) $3 \overrightarrow{AB}$
( B ) $4 \overrightarrow{AB}$
( C ) $2 \overrightarrow{AB}$
( D ) $\overrightarrow{AB}$