The point X represents the incenter of the triangle. ( option B)
The incenter of a triangle is the point where the angle bisectors intersect.
It is equidistant from the three sides of the triangle.
The incenter is the center of the incircle, the largest circle that fits inside the triangle.
line TX is the bisector of angle T
line SX is the bisector of angle S
line RX is the bisector of angle R
Therefore, point X is where the bisector meets and it is the incenter.