Concept:Express AX=B as a system of linear equations and solve for the unknowns x1,x2,x3.Explanation:Let X=x1x2x3.Then AX=B gives the system:x1−x2+x3=42x1+x2−3x3=0x1+x2+x3=2Subtract the third equation from the first:(x1−x2+x3)−(x1+x2+x3)=4−2⇒−2x2=2⇒x2=−1Substitute x2=−1 into the third equation:x1−1+x3=2⇒x1+x3=3Substitute x2=−1 into the second equation:2x1−1−3x3=0⇒2x1−3x3=1From x1+x3=3, get x1=3−x3.Put this in 2x1−3x3=1:2(3−x3)−3x3=1⇒6−5x3=1⇒x3=1Then x1=3−1=2.Therefore, X=2−11.Answer:X=2−11 (Option B).