Take to task about the speed? (4)
I believe the answer is:
rate
I believe this is a double definition.
'take to task' is the first definition.
(thesaurus)
'the speed?' is the second definition.
(the speed at which something happens)
'about' is the link.
(Other definitions for rate that I've seen before include "Severely criticise - speed" , "Value; charge" , "Think highly of; criticise severely" , "Estimate value of - speed" , "Be worthy of; speed" .)