I will give 15 points
2 answers:
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<h3>Answer: Choice A 
</h3>
The R stands for "rotation". The "O" as a small subscript means "origin" which is where the x and y axis cross. The 90 degrees means we rotate 90 degrees counterclockwise. This is equivalent to 270 degrees clockwise, but writing is not correct as we don't rotate 270 degrees counterclockwise.