The isosceles triangle is simply defined as needing to have AT LEAST two sides of equal length, so the equilateral triangle is included within the category of the isosceles triangle. Thus, the best answer is B).
The answer would be (B) since two sides of the triangle are the same. Even if the third side turned out to be another measurement there are no answers that relate to the question apart from (B)
An isosceles triangle has at least 2 sides with the same measurement
