You are creating a custom CSS3 style.
You have the following requirements to complete the style:
Box1 has a red outline.
Box1 contains box2, and box2 must remain inside box1
Box2 must have a green to black gradient.

Box2 must be surrounded by white space.
The style resembles the following diagram:

You need to add the CSS3 code to the styles.
How should you complete the relevant code? (To answer, select the appropriate code segment in each drop-down list in the answer area.)

Hot Area:

Answer: