Identify the Letter of the Choice That Best Matches the Phrase

Identify the letter of the choice that best matches the phrase or definition.
-A separate file that contains a CSS style code

A) cascade
B) breathing room
C) tiling
D) link
E) external style sheet
F) float
G) hexadecimal
H) none
I) bottom right
J) repeat-x
K) background-attachment
L) thin