Code has already been provided to define a variable A that is a matrix with $5$ rows and $6$ columns of numbers $($a $5$ x $6$ matrix$).$ Add commands to the function to perform the operations described below and assign the results to the indicated output variable names.

Create a new $2$ x $6$ matrix, B$,$ that consists of the first and last rows of A$.$

Create a new matrix, C$,$ that consists of the elements at the four corners of A$.$

Create a new $4$ x $5$ matrix, D$,$ that consists of the second through fifth rows in the second through last columns of A$.$