Which sequence correctly represents the bacterial folic acid pathway and the order of the two enzyme targets?

Tetrahydrofolic acid → (enzyme A) → dihydrofolic acid → (enzyme B) → PABA

PABA → (enzyme B) → tetrahydrofolic acid → (enzyme A) → dihydrofolic acid

PABA → (enzyme A) → dihydrofolic acid → (enzyme B) → tetrahydrofolic acid

PABA → dihydrofolic acid → tetrahydrofolic acid → (enzyme A and enzyme B act interchangeably on all steps in a network of redundant enzymes)