2. In each multiple choice question belowg some numbered choices are given and some are correct (wordings like is and are do n_ot indicate the singularity/plurality of the number of correct choices). Answer the question by adding up the numbers of the correct choices. In case all choices are wrong, answer 0. Explanation is n_ot required. (a) Let A and B be a 4 X 3 and 3 x 4 matrix respectively. Which of the following exists? (1) AB (2) BAT (4) ABT (3) ATBT {b} A system of linear equations has a unique solution. Which of the following is a. possible augmented matrix of the system? 1.004 (1) 010? 0011 1000 (2) 11120 0001 10007 01000 (4) 00101 00014 01401 00013 (8) 00000 00000 (c) For a homogeneous system of 5 linear equations with 4 unknowns, which of the following is possible? (1) The solution set is empty. (2) The solution set is a subspace of R4 with dimension 1. 4) The solution set is a subspace of R4 with dimension 2. l 8 The solution set is a subspace of R4 with dimension 3. t C