The objective function `Z=x_(1)+x_(2),` subject to ` x_(1) +x_(2) le 10 , - 2x _(1) +3x_(2)le 15, x x_(1) le 6,x_(1),x_(2) ge 0` has maximum value ________ of the feasible region .
A. At only one point
B. At only one points
C. At every point of the segment joining two points
D. At every points of the line joining two points