Step 1: St. Thomas Aquinas' understanding of God.
St. Thomas Aquinas, a Catholic philosopher and theologian, argued that God is a necessary and supremely perfect being. His arguments for the existence of God include the cosmological argument, the argument from contingency, and the teleological argument.
Step 2: Knowledge of God and True Happiness.
Aquinas believed that human beings can come to know God, but this knowledge is primarily achieved through reason and divine revelation. However, he also asserted that true happiness is found in the vision of God — in perfect union with the divine. This is central to his theological outlook.
Step 3: Analyzing the options.
(A) is incorrect as Aquinas did not assert that knowledge of God is innate.
(B) is correct because Aquinas maintained that true happiness (the ultimate fulfillment) is found in union with God.
(C) is incorrect because Aquinas believed that knowledge of God could be acquired through natural reason but not as an innate concept.
(D) is partially correct in that knowledge of God may be reached by reflection, but it is more accurately a blend of reason and divine revelation.
Step 4: Conclusion.
Therefore, the correct answer is (B), as it directly aligns with Aquinas' view that the ultimate happiness is found in God.