Which two CSS3 styles will achieve the goal?

You are styling a box object on a page by using CSS3.

You need to set the transparency of the object to 50%.

Which two CSS3 styles will achieve the goal? (Each correct answer presents a complete solution. Choose two.)

A . Option A
B . Option B
C . Option C
D . Option D

Answer: B, C

Explanation:

The RGBA declaration allows you to set opacity (via the Alpha channel) as part of the color value.

Example:

div { background-color: rgba(255,0,0,0.5); }

The background color has been set to blue, and the opacity set to half.

Example 2:

background-color: rgb(0,0,255); opacity: 0.5;

The background color has been set to blue, and the opacity set to half.

Reference: A brief introduction to Opacity and RGBA

http://www.css3.info/introduction-opacity-rgba/