The brute force approach is to count all the triangles literally inside the circle you can draw

Just take one point as a reference and then join with another two points. Then the point after until you map the entire circle.

It will not take that much time but is tedious. It is not the way the question is conceived to be solved.

Instead, this is a combinatorics question in disguise

You have seven points and three sides for each triangle

\(\frac{7!}{3!4!}= \frac{7*6*5*4*3*2*1}{3*2*1-4*3*2*1}=35\)

B is the answer