Geometry

Question Analysis：
This question checks your ability to diagnose a common error when reflecting across the line y = x.

Key Concept Explanation:
Correct reflection over y = x requires swapping x and y, and keeping the signs unchanged.

Step-by-Step Solution：
Original point: (–3, 7)
Correct image: (7, –3)
Student’s answer: (–7, 3)
So they swapped and flipped the signs — incorrect.

Option Analysis：
A. Incorrect — reflection over y-axis would give (3, 7)
✅ B. Correct — they swapped, then reversed signs
C. Incorrect — x-axis reflection gives (–3, –7)
D. Incorrect — rotation would change both coordinates differently

Common Mistakes：
Believing reflection involves flippi...