The correct answer option is B. Construct the perpendicular bisector of each side of the triangle.
<u>Step-by-step explanation:</u>
We are given that a student wants to construct a circumscribed circle of a triangle and we are to determine whether which of the given answer options is the first step he should take.
The student needs to first construct the perpendicular bisector of each side of the triangle.
The perpendicular bisectors of each side of the triangle are constructed such that they meet at the center of the circumbscribed circle.
