Which of the following is the Color Format that is the CSS3 HSL value with a fourth value to set the alpha channel value for the color to define the opacity of the element?

Answer: Option A

An HSLa is specified via a function style hsla(hue,saturation, lightness, alpha), where hue, saturation, and lightness are the same as standard hsl() values, and the alpha channel value for defining opacity is a number between 0 (fully transparent) and 1 (fully opaque).