1- Its is Not Idempotent as it does not satisfy Idempotent Property(In algebra, an idempotent matrix is a matrix which, when multiplied by itself, yields itself.That is, the matrix M is idempotent if and only if MM = M. For this product MM to be defined, M must necessarily be a square matrix. ).
2- It is not Orthogonal as it does not satisfy Orthogonal Property( In linear algebra, an orthogonal matrix or real orthogonal matrix is a square matrix with real entries whose columns and rows are orthogonal unit vectors ,) .
3- Check for Symmetric
It is not Symmetric
4- Check For Skew Symmetric
aij = −aji.
It is Skew Symmetric
Hence B is Correct Answer.