Answer:
A. Building of Theater of Pompey.
Explanation:
The Theater of Pompey was built in 55 B.D.
The construction of the Forum of Augustus began building in 20 B.D. and concluded in 2 B.D.
The Altar of Peace (Ara Pacis) was built in 9 B.D.
The Theater of Marcellus is built in 11 B.D.
Hence, the earliest construction is the Theater of Pompey.
