The answer is B: You are much more logical than I.
In formal English we keep I/we, when making comparisons, because the pronoun is still considered to be the subject of the verb, even though when the verb has been ommited: "I am not as old as you (are)". However, the use of me/us is more usual in informal English, as in A: than him; in C: as them; in D: than her.