The triangle slides to a new position.
Which of the following could be the new position of the triangle?

A.

B.

C.

D.

Hint: Slide means to move along a surface without any flipping or rotation.
The relative position of the top-bottom and the left-right will not change in sliding.
An object can slide either horizontally, vertically or in both the directions (diagonally).

Complete step-by-step answer:
Let's look at the answer options one by one:
A.

The other triangle is a vertical mirror image of the original. The left-right sides of the triangles have changed. Since there is a flipping, this is not sliding.
B.

Like in answer option A above, the other triangle is a vertical mirror image of the original. This is also not sliding.
C.

The new triangle has moved two steps up-wards and two steps right-wards. Since there is no change in the sides, but only a movement, this is the case of sliding of an object.
D.


This image is a horizontal mirror image of the triangle. The top-bottom sides of the triangle have changed. Since there is a flipping, this is not sliding.
The correct answer option is, therefore, C.

Note: A $360{}^\circ $ (complete) rotation of an object amounts to no rotation effectively.
A mirror flips the image by $180{}^\circ $ along a line parallel to the placement of the mirror, but it does not rotate it.
Only those objects which are symmetrical about both the horizontal and the vertical axes, will have the same mirror image and $180{}^\circ $ rotated image, about any axis.