The specific religious denomination that Spain and Portugal spread throughout the "New World" is Catholicism. To get this answer, you can consider the historical context of Spain and Portugal's exploration and colonization of the Americas during the Age of Discovery. Both Spain and Portugal were predominantly Catholic countries, and their voyages to the New World were often driven by a desire to spread Christianity. As they established colonies and missions in places such as present-day Latin America, they actively promoted and enforced Catholicism as the dominant religion. Therefore, the correct answer is option A: Catholicism.
