Consider the following observation model b =x+x+1 b2 22-23+ 122 b3 21-423+13 by 21+223 +14 = where [b1b25b3=3 b=4]What is the least square estimate of x = [1,2,3]? (a) x 2.04, 4.52, -0.24] (b) x 2.04 (c) x 6.45 (d) x (6.45, 4.52-0.85]