How can you create a semi-transparent background color?

1.  background-color: hsl(0, 0, 0, 0.5);
2.  background-color: rgbx(0, 0, 0, 0.5);
3.  background-color: rgba(0, 0, 0, 0.5);
4.  background-color: rgba(0, 0, 0, 1);

rgba is a funtion in css. rgba stands for red, green, blue and alpha. The value of alpha can be between 0 and 1 both inclusive with 0 being fully transparent and 1 being fully opaque.

Correct Answer:

•  background-color: rgba(0, 0, 0, 0.5);