The Caucasus Mountains are found between the Black and Caspian Seas.
I believe the awncer is B
Levees and embankments allow humans to c)settle below river level. A levee is defined as "an elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels." This definition can also be used for the term embankment.
The answer would be C. Germany has recently changed the legal retirement age to 67.