Answer:
Queen Isabella of Spain granted the funds to make the first voyage because she was convinced that Christopher Columbus new water route by sailing West on the Atlantic ocean would help Spain in gaining more commercial advantage against the Portuguese.
Step-by-step explanation:
Queen Isabella of Spain funded Christopher Columbus first voyage in the year 1492, because she believed that Christopher Columbus new water route by sailing West on the Atlantic ocean would help Spain in gaining more commercial advantage against the Portuguese who have exclusive rights of navigation and commerce in all of the South of the canary islands of the Atlantic ocean.