Which of the following represent successful predictions (or confirmations) of General Relativity?
A. The demonstration, via gravitational waves in 2015 and the Event Horizon Telescope in 2019, that black hole event horizons exist.
B. The 2003 measurement of the primordial abundance of deuterium compared to hydrogen and helium.
C. The 55 microsecond per day adjustment of the GPS satellite clocks that accounts for their reduced gravity, compared to Earth's surface.
D. The 1964 discovery of the cosmic microwave background radiation.
E. The 1995 discovery of 51 Peg b, the first extrasolar planet discovered in orbit around a Sun-like star.
F. The anomalous precession of Mercury's orbit, as known to Einstein in 1915.
G. The 2015 detection of gravitational waves.
H. The additional bending of starlight near the limb of the Sun observed during the 1919 solar eclipse.