Final answer:
Joshua's theophanic encounter, a divine or supernatural appearance, did affirm his leadership to the people of Israel, making the answer A. True.
Step-by-step explanation:
The question is asking whether Joshua's theophanic encounter affirmed his leadership to the people of Israel. The term 'theophanic encounter' can be understood as an event where a divine or supernatural appearance, in this case of Yahweh, affirms or signifies a particular divine will or message. Considering the historical context of Joshua's leadership in the Bible and his subsequent military campaigns where he had the Lord's approval, it can be argued that such encounters did affirm his leadership to the people of Israel. Therefore, the correct answer to the question would be A. True.