For acceptable order questions, go through the rules and use them to eliminate answers one by one.
Rule 1 eliminates C. If Q runs, then Q must be directly before T.
Rule 2 eliminates B. Smith can’t run second or fourth.
Rule 3 eliminates E. If U is not running, then R must run second.
Rule 4 eliminates A. If R is second, U can’t run.
D is CORRECT. It violates no rules.

Hi! Just a reminder that D is the correct answer.
Hi,
Thanks for catching this typo! The page has been updated.