Let A-axis team consist of XA, YA, and ZA vectors, and B axis team consists of vectors XB, YB, and ZB. Let the expression of the origin of the A-axis set on the B-axis set be denoted by BPAORG. Let BVA denote the representation of the vector VA on the B axis set. Let it be defined as BAR = [BXA BYA BZA].

BAR BPAORG
0 0 0 1

Let the 4x4 matrix given as BAT. So what is the result of BAT ACT CBT matrix multiplication?

Matrix whose diagonal elements are zero and whose other elements are a
Zero matrix
A matrix whose all elements are one
Identity matrix