[amp_mcq option1=”Sentence is satisfiable” option2=”Sentence is unsatisfiable” option3=”Sentence remains the same” option4=”None of the mentioned” correct=”option1″]
The answer is: A. Sentence is satisfiable.
Resolution is a proof system in propositional logic. It is called refutation-complete if every unsatisfiable sentence has a resolution refutation. In other words, if a sentence is unsatisfiable, then there is a sequence of resolution steps that starts with the empty clause and ends with the sentence itself.
Option B is incorrect because a resolution refutation does not necessarily prove that a sentence is unsatisfiable. It is possible for a resolution refutation to exist even if the sentence is satisfiable.
Option C is incorrect because a resolution refutation does not necessarily change the sentence. The resolution steps only remove clauses from the set of clauses being considered.
Option D is incorrect because one of the options is correct.