When the points are set for main line, point indicator shows white target by day and ________ Light by night. A. Red B. Green C. Yellow D. White

The correct answer is White.

A point indicator is a device that is used to show the position of the points on a railway track. It consists of a white target that is visible during the day and a white light that is visible at night. When the points are set for the main line, the white target is visible during the day and the white light is visible at night.

The other options are incorrect because they are not the colors that are used by point indicators. Red is the color that is used to indicate a stop signal, green is the color that is used to indicate a go signal, and yellow is the color that is used to indicate a caution signal.