A teacher's last selection for class (7)
I believe the answer is:
arrange
'class' is the definition.
(thesaurus)
'a teacher's last selection' is the wordplay.
'last' suggests the final letters.
'selection' becomes 'range' (I've seen this before**).
The last letter of 'teacher' is 'r'.
'a'+'r'+'range'='ARRANGE'
'for' is the link.
(Other definitions for arrange that I've seen before include "Dispose" , "Bring about or put in order" , "Set in place" , "Orchestrate - order" , "Put in order; make plans" .)