Well, if you think logically, B is never the answer.
I believe you are somewhat young, "XD" is a giveaway (Though I shouldn't assume your age, it's rude, my apologies). They will never let you take over the world, even if you may be convincing.
A giant robot army would take a while to make, but plans take a while to make so you could consider it. It does depend on how many you would like to make. An army can consist of a few hundred, to a few hundred thousand, though in this case maybe a thousand may be useful.
Ally with larger armies would be useful, you would get plenty of firepower, possibly all over the world. You should probably ally with armies in many countries, allowing you to cover as much ground as possible. This would take a while, though maybe not as long as the robot army.
All of the above is most likely the best option, you can ally with larger armies and make that robotic army of yours, and you would have a few backup plans in case anything goes wrong.
So I would go with D, All of the above.