Let A =  $\hat{\mathbf{i}}A\cos \theta +\hat{\mathbf{j}}A\sin \theta$ be any vector. Another vector B which is perpendicular to A can be expressed as

• A

  $\hat{\mathbf{i}}B\cos \theta -\hat{\mathbf{j}}B\sin \theta$

• B

  $\hat{\mathbf{i}}B\sin \theta -\hat{\mathbf{j}}B\cos \theta$

• C

  $\hat{\mathbf{i}}B\cos \theta +\hat{\mathbf{j}}B\sin \theta$

• D

  $\hat{\mathbf{i}}B\sin \theta +\hat{\mathbf{j}}B\cos \theta$