Adverbial placement in English can significantly alter the ...
(__) Negative adverbials such as "seldom" or "under no circumstances" trigger subject-auxiliary inversion when placed in the initial position of a clause.
(__) Focus adverbs should be placed immediately before the constituent they modify to avoid semantic ambiguity in formal registers.
(__) Adverbs of frequency must be positioned before the auxiliary verb "be" in all indicative sentences regardless of the presence of other modals.
(__) Viewpoint adverbs like "theoretically" function exclusively as adjuncts and are strictly prohibited from appearing in the initial sentence position.
After analysis, choose the alternative that presents the CORRECT sequence: