Do all of the properties stated below need to be met for a matrix to be characterized as invertible or only one being met is okay?

Question

• A is an invertible matrix
• A is row equivalent to the identity matrix
• A has n pivot columns The equation has only a trivial solution to ax=0
• The columns of A are linearly independent
• The equation Ax=b has at least one solution for each b in Rn
• The column of A span Rn maps Rn onto Rn
• There is a nxn matrix C such that CA is equal to the identity matrix
• There is an nxn matrix D such that AD is equal to the identity matrix