Chooses the new post (4)
I believe the answer is:
opts
'chooses' is the definition.
(I've seen this in another clue)
'new post' is the wordplay.
'new' indicates anagramming the letters.
'post' is an anagram of 'OPTS'.
'the' acts as a link.
(Other definitions for opts that I've seen before include "Makes a choice from a range" , "Selects between alternatives" , "Settles" , "Picks needed" , "Elects" .)