Answer : 3. "इसरो"
Explanation :

The Indian Space Research Organization has announced plans to launch its first X-ray Polarimeter Satellite (XPoSat) with the aim of investigating the polarization of intense X-ray sources. Mission objectives include measurement of X-ray polarization in the energy band of 8-30 keV emanating from X-ray sources and long-term spectral and temporal study of cosmic X-ray sources in the energy band of 0.8-15 keV. The life of the mission is expected to be 5 years.