Resposta :
[tex]\Large\boxed{\begin{array}{l}\sf V_M=\dfrac{\Delta_S}{\Delta_T}\\\\\sf V_M=\dfrac{420~ km}{6~ h}\\\\\sf V_M= 70\,km/h\\\huge\boxed{ \boxed{ \boxed{ \boxed{ \sf \dagger \maltese~ alternativa~B}}}}\end{array}}[/tex]
[tex]\Large\boxed{\begin{array}{l}\sf V_M=\dfrac{\Delta_S}{\Delta_T}\\\\\sf V_M=\dfrac{420~ km}{6~ h}\\\\\sf V_M= 70\,km/h\\\huge\boxed{ \boxed{ \boxed{ \boxed{ \sf \dagger \maltese~ alternativa~B}}}}\end{array}}[/tex]