CAYLEY 2019 Problem 12

In a regular pentagon, the measure of each interior angle is 108^{\circ}. If P Q R S T is a regular pentagon, then the measure of \angle P R S is

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Answer Choices
A. 72^{\circ}
B. 54^{\circ}
C. 60^{\circ}
D. 45^{\circ}
E. 80^{\circ}