Final answer:
Prince Henry of Portugal, called "the Navigator", is best described as sponsoring exploration and navigation.
Step-by-step explanation:
Prince Henry of Portugal, called "the Navigator", is best described as sponsoring exploration and navigation. Under his sponsorship, Portugal began exploring the coast of Africa in order to trade and extend Christianity. Prince Henry established a school for navigational studies in Portugal, which played a vital role in the success of Portugal's exploration efforts.