A. Stonehenge was created ... in a single phase over 1400 years, starting around 3000 BCE

B. in 3 different phases over 1400 years, starting around 30,000 BCE
C. in 2 different phases over 1400 years, starting around 3,000 BCE
D. in 3 different phases over 1400 years starting around 3,000 BCE

D. in 3 different phases over 1400 years starting around 3,000 BCE