Explanation:

- INSAT: This is a series of multipurpose geostationary satellites commissioned by the Indian Space Research Organisation (ISRO) to cater to telecommunications, broadcasting, meteorology, and search and rescue operations. However, it's not the first experimental geostationary satellite.

- VSLV-3: This option seems like a typo or misrepresentation, as no known VSLV-3 exists.

- SLV-3: This stands for Satellite Launch Vehicle-3, India's first experimental satellite launch vehicle. It was not a satellite, but a launch vehicle.

- APPLE: Correct Answer. The Ariane Passenger Payload Experiment (APPLE) was India's first three-axis stabilized geostationary experimental communication satellite, launched in 1981. It laid the foundation for future INSAT series satellites.

So, the correct answer and India's first geostationary experimental telecommunications satellite is APPLE.