What is the contrapositive of the following statement?

If ∆ABC is equilateral, then it is isosceles.


If ∆ABC is not isosceles, then it is not equilateral.


If ∆ABC is isosceles, then it is equilateral.


If ∆ABC is equilateral, then it is isosceles.


If ∆ABC is not equilateral, then it is not isosceles.