Used until the end of the Second World War,the German army

Used until the end of the Second World War, the German army employed the U-boat to attack both military or civilian watercraft.

A the German army employed the U-boat to attack both military or
B the U-boat was employed by the German army to attack both military and
C the U-boat employed the German army to attack both military or
D the German army had employed the U-Boat to attack both military and the
E the U-boat has been employed by the German army to attack both military and also


after narrowing down to B & E.

Used until the end of the Second World War

I feel "until" specifies time frame so has been employed is more appropriate than was employed.

I agree both military and also is wrong grammar and is enough to eliminate option E, But i just want to find out if Usage "has been employed" is more apt than was employed