The idiom here is "based on" or "based upon" SOMETHING, so your opinion should be based on some noun. While "comparing" in E is technically a noun, gerunds are somewhat second-rate in situations like this, as they tend to suggest verbs, or at least something that isn't static. (It sounds funny to "base", or firmly place, something on a verb, or a noun suggesting one.) So the best way of expressing the idea is to clearly base your idea on an unambiguous noun: "a comparison" or "comparisons".