Answer:
C'=(4,6)
Explanation:
The reflexion of a point P with coordinates (x,y) over the line y=x is the point P' with coordinates (y,x). For example, the reflection point of a with coordinates (10,2) is a' with coordinates (2,10).
For this reason, the point c y reflect in C' with coordinates (4,6).
The solution is also shown in the attachment.