Choice B
First, men by nature are depraved. Second, God is perfect. God does not <em>need </em>us nor did he <em>need </em>Abraham. Abraham could not trade anything with God that God had already given him. So, Choice A is wholly incorrect.
God is omnipresent. God also does not make covenants with the wicked. If God made a covenant with Abraham, then there will be interaction between the two parties. God does not interact with the wicked, therefore there is no covenant between him and the unrighteous. So, Choice C is inaccurate.
God does not attack his friends. (Yes, I said "friend". You may think it is callous of me, but read your Bible. In James 2:23 Abraham is called a "friend of God.") God does not conquer or take advantage of us, nor did he to Abraham. Choice D is erroneous.
That leaves us with Choice B, which is the correct answer. In Psalm 91, God is referred to as a "refuge" and "protection" as He is with everyone he is in covenant with. Abraham agreed to abide by God's laws in exchange for an eternity in Heaven -- or, if you'd rather me say, "protection."
Answer: Choice B