Solution:
Keep in mind:
When a point (a,b) is reflected across a line , y=x the coordinate of new point after reflection becomes (b,a).
Also , when point (a,b) is reflected across a line , y= -x the coordinate of new point after reflection becomes (-b,-a).
So, option (B) r ,(Line, y=–x),Preimage → (x, y) → (–y, –x)→image, and Option (C) r (Line, y=x),Preimage→ (,x, y) → (y, x) →Image, are true options describing the rule of reflection across lines, y=x,and y= -x.