What should be written in the blank of the code for JQuery

What should be written in the blank of the code for JQuery Code Used to Apply CSS3 Animations?

Code:
_________ leftmove {
100% { transform: translateX(-70px); opacity: 1; }
}
_________ rightmove {
100% { transform: translateX(70px); opacity: 1; }
}
<script>
$(function() {
var footerBottom = $("#articlefooter").offset().top + $("#articlefooter").height();
$(window).scroll(function() {
if ($(this).scrollTop() > (footerBottom - $(window).height())) {
131
$("#prevpage").css('animation', 'leftmove 1s 2s forwards');
$("#nextpage").css('animation', 'rightmove 1s 1s forwards');
});
});
</script>

1. animation-name
2. @media
3. !important
4. @keyframes
5. None of these

Correct Option: A

@keyframes

CSS Animations

CSS

Correct Option: A