A. progress
B. liberty
C. zenith
D. modernity
Nadir : the lowest or most unsuccessful point in a situation.
progress : forward or onward movement towards a destination.
Liberty : the state of being free within society from oppressive restrictions imposed by authority on one’s way of life, behaviour, or political views.
Zenith : highest point.
Modernity : the quality or condition of being modern.
Antonym of Nadir is Zenith