Question the method (3)
I believe the answer is:
how
This clue is a double definition.
'question' is the first definition.
(how is a question word)
'method' is the second definition.
(I've seen this in another clue)
'the' is the link.
(Other definitions for how that I've seen before include "See 16" , "In what way?" , "By what means?" , "In what manner or method?" , "Who (anag.)" .)