Temptation

Lurcher "obedience". This is 2 seconds after I called Hendricks to heel. Could it be:
a) His brain cell (singular) hasn't yet registered the command?
b) On principle, he won't respond until the 5th time I say it?
c) He's calculating how long it would take him to sprint to that treeline and FREEDOM!!?
(Knowing my dog, my money's on mostly b, with a hint of c! :D)