The station where observations are not made, but the angles at the station are used in triangulation series, is known as A. Satellite station B. Subsidiary station C. Pivot station D. Main station

The correct answer is: A. Satellite station

A satellite station is a station where observations are not made, but the angles at the station are used in triangulation series. The angles at a satellite station are measured from the main station, and these measurements are used to calculate the position of the satellite station.

A subsidiary station is a station where observations are made, but the angles at the station are not used in triangulation series. The observations at a subsidiary station are used to calculate the position of the subsidiary station, but they are not used to calculate the position of other stations in the triangulation series.

A pivot station is a station where observations are made, and the angles at the station are used to calculate the position of the pivot station and the positions of other stations in the triangulation series.

A main station is a station where observations are made, and the angles at the station are used to calculate the position of the main station and the positions of other stations in the triangulation series. The main station is usually the most important station in a triangulation series, and it is often the station from which the other stations are measured.