The correct answer is False.
The @keyframes rule is used to define the properties that will control the animation of an element. It is not used to control the audio/video formats.
The @keyframes rule is used to define the keyframes of an animation. A keyframe is a specific point in time in an animation, and the properties of an element at a keyframe are defined using the CSS properties. The @keyframes rule is used in conjunction with the CSS animation property to create an animation.
The CSS animation property is used to create an animation of an element. The animation property takes a list of keyframes as its value, and the properties of the element at each keyframe are defined using the CSS properties. The animation property also takes a number of other properties that control the timing, duration, and direction of the animation.
The audio/video formats are controlled using the CSS media queries. The media queries are used to specify the presentation of a document based on the capabilities of the user’s device. The media queries can be used to specify the presentation of audio and video content based on the user’s device.