Pick clubs and hearts over diamonds (6)
I believe the answer is:
Here is my best explanation:
'pick' is the definition.
('choice' can be a synonym of 'pick')
'clubs and hearts over diamonds' is the wordplay.
'clubs' becomes 'c' (abbreviation used in card games such as bridge).
'and' says to put letters next to each other.
'hearts' becomes 'h' (abbreviation used in card games e.g. bridge).
'over' becomes 'o' (cricket abbreviation**).
'diamonds' becomes 'ice' (I've seen this before).
(Other definitions for choice that I've seen before include "Plum", "Excellent", "Possibility", "'Selection, option (6)'", "of superior quality", "Will", "Very good", "Pick", "Act or power of selecting" and "Select".)