Which statement explains why a german submarine sunk the lusitania?
germany wanted to draw the u. s. into the war.
the german commander mistook it for a warship.
germany practiced unrestricted submarine warfare.
germany had warned americans not to travel on british ships.

I believe the answer is: Germany practiced unrestricted submarine warfare.

In restricted werfare, all of the countries would agree that they would not attack the submarines that are not a part of the warships. (such as passenger ships). The Gerrmany choose to adopt unrestricted warfare and sunk one of England's passenger ship.

#2 the answer is d

#3 the answer is a

#4 the answer is b