请帮我讲一下这道题---**Textual Information:** A certain open star cluster contains M-type stars and K-type stars. The estimated total mass of M-type and K-type stars in this open star cluster is 129,492 quettagrams. The graph shown models the possible combinations of the number of M-type stars, $x$, and K-type stars, $y$, that could be in this open star cluster if all the M-type stars have the same estimated mass and all the K-type stars have the same estimated mass. Based on the graph, which of the following is closest to the estimated mass, in quettagrams, of each M-type star in this cluster? **Options:** A) 830 B) 959 C) 55,622 D) 73,870 **Chart/Diagram Description:** * **Type:** Line graph. * **Main Elements:** * **Coordinate Axes:** * X-axis: Labeled "Number of M-type stars". Scale goes from 0 to 160, marked every 20 units (0, 20, 40, 60, 80, 100, 120, 140, 160). * Y-axis: Labeled "Number of K-type stars". Scale goes from 0 to 140, marked every 20 units (0, 20, 40, 60, 80, 100, 120, 140). * Origin (O) is at (0,0). * **Line:** A single straight line sloping downwards from the Y-axis to the X-axis. * **Points:** * Y-intercept: Approximately at (0, 140). This represents 0 M-type stars and 140 K-type stars. * X-intercept: Approximately at (160, 0). This represents 160 M-type stars and 0 K-type stars.