Bidder's option (4)
I believe the answer is:
pass
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">bidder's option</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for pass that I've seen before include "Blow over" , "sticky situation if one is pretty" , "OK" , "Go by; mountain route" , "Exam success" .)