Knowing how to represent a binary relation in the form of a binary matrix

Given a set A, a binary relation R among the elements of A is a subset of the cartesian product A x A ( =A2 ). We said that $a$ is in relation with $b$ if $aRb$. Matrices are table-like structures that represent a binary relation. You will now see how the following relation (cRb, dRa, bRd) applies to the elements of the set

A = {a,b,c,d}

And how it is depicted in a matrix.

matrix 1


Check the correct boxes in the empty matrix below to specify the following relation on the set A = {a,b,c,d}
R = {(a,a), (a,b), (b,d), (c,b), (c,c), (d,a), (d,c)}

  a b c d