An example of a longitudinal wave would be the first option:
"A wave traveling down a stretched Slinky toy, with both ends held
fixed"
A longitudinal wave is a wave that oscillates in the same direction that the wave moves.
For example, the option D would not be a longitudinal wave, as the wave travels along the string direction, but the oscillations would be up and down, so this is a transversal wave.
Similarly with option C, water waves, where you can see how the waves expand radially with peaks and throughs, but again, the peaks and throughs are perpendicular to the motion direction, so again this is not a longitudinal wave (the same thing happens with the wave on the surface of a drum, only that here the patterns may be a lot more complex).
Finally, the correct option is A.
The oscillations on a spring are back and forth, so the oscillations are in the same directions than the wave motion, thus, these are longitudinal waves.
If you want to learn more about waves, you can read:
https://brainly.com/question/15531840
