The geographic location of constantinople, the capital of the byzantine empire,

a)prevented invasions from rival empires.
b)allowed for trading contacts with europe, africa, and asia.
c)made it prone to flooding and constant trade interruptions.
d)enabled overland, but not overseas, trade with europe and asia.

A)prevented invasions from rival empires.

Explanation:

The constanipoles are the capital of the roman eastern empire and were framed for its massive and complex difference and thus the first wall of the city was erected that surrounded the city both on land and the seafronts. And this defense was the most sophisticated system of the Antiquity as it was located between the massive golden horns and the Marmara sea.