Different semantic structures for identically-structured drop-down menus

Being purely CSS-based, these require no javascsript. For some UIs, in order to pull down the pull-down menus, you need a single tap on the header part.

Option 1: menu as heirarchical ul's

Option 2: menu as non-heirarchical dl's and dd's

Option 3: menu as plain old div's

Option 4: menu as rows in a table