What is the Hagia Sophia?

A.
the first theater established to carry on the Greek dramatic tradition in the Byzantine Empire

B.
a church building recognized as a great architectural achievement of Justinian's reign

C.
the code of law written for the Byzantine Empire during Justinian's reign

D.
the summer home of Theodora's mother and the site of her first meeting with Justinian

Answer :

The Hagia Sophia is B) a church building recognized as a great architectural achievement of Justinian's reign. It was an Eastern Orthodox Cathedral, which was then converted to an Imperial Mosque and then secularized as a museum.It is located in Istanbul, which is one of Turkey's largest cities. When it was a mosque, it served as an inspiration for many other mosques and when it was church, because of it's massive dome, it is said to changed the history of architecture forever.

B.  a church building recognized as a great architectural achievement of Justinian's reign

I visited the place while I was in the air force, it is in Istanbul, Turkey.

Hope that helped