BRAINIEST AND 30 POINTS PLS HELP !!!

Triangle ABC is a right triangle, Point is the midpoint of side AB, and point E is the midpoint of side AC. The measure of

The proof, with a missing reason, proves that the measure of
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Which of the following can be used to fill in the missing reason?
A. Triangle Inequality Theorem
B. Midsegment of a Triangle Theorem
C. Concurrency of Medians Theorem
D. Isosceles Triangle Theorem