CAYLEY 2021 Problem 8

A square piece of paper has a dot in its top right corner and is lying on a table. The square is folded along its diagonal, then rotated 90^{\circ} clockwise about its centre, and then finally unfolded, as shown.

The resulting figure is

Answer Choices
A. caley 2021 8a
B. caley 2021 8b
C. caley 2021 8c
D. caley 2021 8d
E. caley 2021 8e