'Neighbour' in the Bible

And he, answering, said, Have love for the Lord your God with all your heart and with all your soul and with all your strength and with all your mind; and for your neighbour as for yourself.

But he, desiring to put himself in the right, said to Jesus, And who is my neighbour?

Which of these three men, in your opinion, was neighbour to the man who came into the hands of thieves?