What is the result of multiplying two matrices?

A matrix multiplication is only possible if the number of columns of the first matrix is equal to the number of rows of the second matrix.
The result of multiplying two matrices is a matrix whose elements are obtained by multiplying the corresponding elements of the rows of the first matrix by the corresponding elements of the columns of the second matrix and adding the products.
The order of the matrices in the multiplication does not matter.
The product of two matrices is always a square matrix.
a) Only I and II are correct.
b) Only II and III are correct.
c) Only I, II, and III are correct.
d) Only II, III, and IV are correct.