A probability matrix is a square matrix having two properties: (i) every entry is a nonnegative real number, and (ii) the sum of the entries in each row is 1. Let a, b, c, d e (0, 1) be given. Let -(:) 1- a 1- c A = B = b 1-6 d 1-d Which of the following is true. (a) The transpose of A is a probability matrix if and only if a +b+ 1. (b) A is not a probability matrix (c) B is not a probability matrix (d) AB is a probability matrix (e) None of these