How have german shepherds' military training affected their ability to adapt to family life?

it makes them well-suited for family life because of their obedience training.
it means that they are unsuitable as a family dog because they have been taught to be aggressive.
it means that they are likely to get out of control because their handler is not there.
it makes them unsuitable for family life because of their military training.

Read this excerpt from i never had it made. "it's all that ought to count," he replied. "but it isn't. maybe one of these days it will be all that counts. that is one of the reasons i've got you here, robinson. if you're a good enough man, we can make this a start in the right direction. but let me tell you, it's going to take an awful lot of courage." he was back to the crossroads question that made me start to get angry minutes earlier. he asked it slowly and with great care. "have you got the guts to play the game no matter what happens? " "i think i can play the game, mr. rickey," i said. the next few minutes were tough. branch rickey had to make absolutely sure that i knew what i would face. beanballs would be thrown at me. i would be called the kind of names which would hurt and infuriate any man. i would be physically attacked. could i take all of this and control my temper, remain steadfastly loyal to our ultimate aim? which is the central idea of this excerpt?