The most popular sport in the Spanish-speaking countries in the Caribbean is baseball. To arrive at this answer, we can consider several factors. Firstly, baseball has a long history and cultural significance in the Caribbean, particularly in countries such as the Dominican Republic and Cuba. Secondly, many successful baseball players from these countries have gained international recognition, further contributing to the sport's popularity. Finally, the level of participation and fan following for baseball in these countries is higher compared to other sports like basketball or soccer. Therefore, the correct answer is baseball.
