In which place of Switzerland there is an observation terrace and scientific observatory at the top of the mountain?
The correct option is B Jungfraujoch
The Sphinx Observatory is an astronomical observatory located above the Jungfraujoch in Switzerland. It is named after the Sphinx, a rocky summit on which it is located. At 3,571 m (11,716 ft) above mean sea level, it is one of the highest observatories in the world.