$A^2−A=0$, where A is a $9×9$ matrix. Then
(a) A must be a zero matrix (b) A is an identity matrix
(c) rank of A is $1$ or $0$ (d) A is diagonalizable.
here the eigen values of the matrix are 0 and 1. so (a) and (c) are not true. i am confused between the other two options.