Which two C5S3 styles will achieve the goal? (Each correct answer presents a complete solution

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 C5S3 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