What did Otis argue about?

(C)

Step-by-step explanation:

Whenever a triangle has two sides congruent, then that triangle is known as an isosceles triangle.

Now, it is given that there is a triangle with one right angle, thus the triangle will be right angled and also that triangle has two sides congruent, then this triangle will be a right angled isosceles triangle.

Since, a scalene triangle has all the sides unequal in measure, therefore, the given triangle will be definitely a right angled isosceles triangle.

Hence, option C is correct.