Concept:To solve for m, isolate the variable on one side by performing the same operation on both sides of the equation.Explanation:Start with the given equation: −1=2−m.Add m to both sides to bring the variable to the left side: m−1=2.Now add 1 to both sides to remove the constant from the left: m−1+1=2+1.This simplifies to m=3.Therefore, the value of m that satisfies the equation is 3.Answer:m=3Correct option is D. 3.