Concept:Equating exponents after simplifying the given equation.Explanation:Given: xmn=(xm)n and n=3.Since (xm)n=xmn, the equation becomes xm3=x3m.For x>0 and x=1, exponents must be equal: m3=3m.Solve: m3−3m=0 → m(m2−3)=0 → m=0 or m=±3.Among the given options, 3 is listed.Answer:m=3