Final answer:
The statement 'This medicine is messing with my head' is true for the use of an uncontactable copula BE. 'Is' acts as the verb 'to be', followed by the adjectival phrase 'messing with my head'.
Step-by-step explanation:
The sentence 'This medicine is messing with my head' does indeed contain an obligatory context for the uncontactable copula BE. The statement 'This medicine is messing with my head' is true for the use of an uncontactable copula BE. 'Is' acts as the verb 'to be', followed by the adjectival phrase 'messing with my head'.
The sentence utilizes the verb is, which is a form of the verb to be (am, is, are, was, were). According to the rules stated, the sentence pattern for the be verb must be followed by an adverbial of time or place, an adjectival, or a noun phrase. In the given sentence, 'messing with my head' acts as an adjectival phrase describing the subject's state due to the medicine. Therefore, the correct answer to the question is A. True.