Is there a better shortcut for "go to next sentence" in Xcode

In Xcode, if I type nsmut then escape, I am offered a range of NSMutable suggestions (NSMutableArray, NSMutableSet, etc.). I am using the arrow keys to get the one I want. It makes me take my fingers off the home keys.

I was wondering if there is another keyboard shortcut for selecting the next and previous selection in the dropdown menu that appears. If not, is there a way to add a keyboard shortcut for this?