(A) "Gigantic" and (B) "Lovely" are adjectives, and they do not have corresponding adverb forms in English.

(C) "Lovingly" is the adverb form of "loving." It describes how something is done in a loving manner.

(D) "Oratory" is a noun, and its adverb form is "oratorically," which describes something related to oratory or public speaking.

(E) "Frantically" is the adverb form of "frantic." It describes how something is done in a frantic, hurried, or wild manner.

So, the correct options are (C) and (E) as they represent the adverb forms of their respective words, while (A) and (B) are adjectives, and (D) is a noun, so they do not have adverb forms.