If PQRS is a parallelogram, then \[\angle \mathbf{P}-\angle R\] is equal to

• A.  \[{{60}^{{}^\circ }}\]                       
• B.  \[~{{90}^{{}^\circ }}\]            
• C.  \[{{80}^{{}^\circ }}\]                                   
• D.  \[{{0}^{{}^\circ }}\]