The lecturer has to make a choice (5)
I believe the answer is:
elect
'make a choice' is the definition.
(electing is a kind of making a choice)
'the lecturer has' is the wordplay.
'has' indicates a hidden word.
'ELECT' is hidden within 'the lecturer'.
'to' is the link.
(Other definitions for elect that I've seen before include "Return" , "Vote into office" , "Choose by vote" , "Preferred" , "special people" .)