Consider an instance of the Satisfiability Problem, specified by clauses Q over a set of Boolean variables , . . . ,In. We say that the instance is monotone if each literal in each clause consists of a nonnegated variable; that is, each literal is equal to ri, for some i, rather than Monotone instances of Satisfiability are very easy to solve: They are always satisfiable, by setting each variable equal to 1. For example, suppose we have the three clauses This is monotone, and indeed the assignment that sets all three variables to 1 satisfies all the clauses. But we can observe that this is not the only satisfying assignment; we could also have set r and r to 1, and r3 to 0. Indeed, for any monotone instance, it is natural to ask how few variables we need to set to 1 in order to satisfy it Given a monotone instance of Satisfiability, together with a number k, the problem of Monotone Satisfiability with Few True Variables asks: Is there a satisfying assignment for the instance in which at most k variables are set to 1? Prove that this problem is NP-complete