Answer : 4. "36000 km "
Explanation :

A geostationary orbit, geostationary Earth orbit or Geosynchronous Equatorial Orbit (GEO), is a circular orbit 35786 km (22236 mile) above the Earth’s equator and following the direction of the Earth’s rotation. An object in such an orbit has an orbital period equal to the Earth’s rotational period (one sidereal day).