Hi Mikey!
Please forgive me, but your post made me smile!
The way you answer a simple causation essay like this one at A-level is 'analytically'.
That means that you construct a list of causes, and then you give a paragraph to each one, remembering to
PELE every paragraph - making the
Point, then
Explaining how it caused the thing in the title, whilst making sure you
Link each cause to the other causes to construct an integrated 'web' of causation, and citing
Evidence which supports your claims and suggestions.
Now, I notice that your teacher has given you the list of points, and if I now tell you all the explanations, where - I wondered - is your part in this essay!

Sorry - I'm just being cheeky!
Speaking more seriously, your teacher HAS given you the list of points, and your job now is to construct the explanations.
You will have to do this yourself, but I will give you some clues.
1. The role of Bismarck - look at the policies he pursued leading up to unification, and think HOW each one helped to bring unification nearer.
2. The decline of Austria - the ruler of Austria was Holy Roman Emperor, and therefore had a great political influence over the tiny German states. How would he feel about unification under Prussia, and why did the declining power of Austria therefore help unfiiation?
3. Prussian military strength - what part did this play in the process of unification and when (especially, there is a specific event I am thinking of)
4. Prussian economic strength - again, there is a specific historical event, usually cited as the beginning of the unification process, which you need to mention)
5. The attitude of other states - France was rabidly anti-unification, and therefore needed to be militarily defeated, but what about the others? What would have happened if they had ALL been rabidly anti-unification. What bought them off?
6. The actions of Napoleon - see below.
Now remember also that at A-level you are not looking at mono-causal explanations. You need, for each point, to be able to explain
a number of ways in which each point caused the event in question.
An example would be for Napoleon.
Napoleon helped to stimulate unification in many ways.
a. Firstly, he united the Germans in hatred to the French domination!
b. He also united Germany politically, doing away with the hundreds of tiny states, and lumping them together into larger units; Napoleon was the end, essentially, of the Holy Roman Empire.
c. Historians also see a link between the principles of the French Revolution, and the growth of 'nationalism', and they therefore date the German unification movement back to then.
d. Napoleon permanently dinted the power of Austria but Prussia came out of the Napoloenic wars stronger than before.
Can you see how you can therefore offer, for Napoleon, a multi-causal explanation of how he helped unification?
Finally, don't forget to end with a conclusion which:
1. draws all the 'link' points together and makes explicit the causal 'web' whereby all the 'points' worked together to cause unification.
2. where valid, this is a good time to mention individual historians, and cast a nod to historiography.
Hope this helps, and please forgive my slight mocking at the start.