Which statement shows the following conditional statement written as a biconditional? "If a triangle is scalene, then the triangle has no congruent sides."

If a triangle has no congruent sides, then the triangle is not scalene.
A triangle is scalene if and only if it has no congruent sides.
A triangle is equilateral if and only if it is not scalene.
If a triangle has some congruent sides, then the triangle is not scalene.