Multi-choice problem: Choose from the options at the end, and answer how do you do this: How to increase the volume on Youtube

Pick from:
(a). On the lower left corner of the video screen, find the button that looks like a speaker. Hover the mouse pointer over it, until a volume slider appears. Move the slider to the right, until the desired volume is reached.;
(b). On the lower left corner of the video screen, find the button that looks like a speaker. Hover the mouse pointer over it, until a volume slider appears. Move the slider to the left, until the desired volume is reached.;
(a).