E20) kindly explain this question.

20. The following non-homogeneous system of linear equations 3x-y + 2z = a 2x y + z = b X + Z= C where a, b, c are real numbers, has (A) solutions for all values of a, b, c (B) solutions for those a, b, c satisfying a = b = c (C) solutions for those a, b, c satisfying a + b + C = 0 (D) solutions for those a, b, c satisfying a - b - C = 0