It is best to use organization when a piece of writing discusses one subject before moving onto another subject.

a.cause and effect
b.spatial
c.topical
d.compare and contrast

I would say that it's best to use D, compare and contrast. In a compare and contrast writing, two subjects are being compared and contrasted. Depending on how you organize your writing, you can talk about one subject first and then the other. 

If you could hear, at every jolt, the blood 
Come gargling from the froth-corrupted lungs, 
Obscene as cancer, bitter as the cud
Of vile, incurable sores on innocent tongues,
My friend, you would not tell with such high zest
To children ardent for some desperate glory, 
The old Lie; Dulce et Decorum est 
Pro patria mori.
(((The poet rebukes readers for their mistaken belief that war is glorious)))