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 space between the section column and the main column

A) bottom
B) relative positioning
C) widget sidebars
D) aside
E) header
F) wrapper
G) document flow
H) gutter
I) placeholder text
J) fixed-width
K) broken
L) fluid