Question: Which color value will create a background color that is semitransparent?

1. `rgb(18, 138, 125)`
2. `#128a7d`
3. `rgba(18, 138, 125,.5)`
4. `hsl(174, 77%, 31%)`

Answer: The correct answer of the above question is Option C:`rgba(18, 138, 125,.5)`