It's in the imperative form, which is just the verb stem without any inflection
What I get from here is to differentiate between the noun "sayansi" (science) and the adjective/adverb "kisayansi" (scientific/scientifically). From that, I get that "kisayasi" must be affecting the verb "tofautisha" here.
Since "tofautisha" means compare/differentiate, the sentence must be a. Compare (these things) scientifically!, or b. Differentiate (these things) scientifically
(Which is what I'm now trying to do with the possible answers.) I think it is a functioning example. For me, the answer is also respresented in the dictionary hints.