"French pirates or corsairs, a nuisance in times of peace, had become a menace to Spanish shipping and to the Spanish economy as relations between France and Spain deteriorated in the 1550s. In 1556-60, the Crown's revenue from the New World fell to half of its levels in the previous years, with much of the treasure stolen by French corsairs who preyed on Spanish vessels along the sea lanes that connected Spain and the Caribbean. For Spain's homeward-bound mariners, one of those sea lanes lay along the Atlantic Coast of North America ... A Spanish base on the Florida coast, then, would help protect the homebound silver fleets." -David J. Weber, historian, The Spanish Frontier in North America, 1992 The main point of this excerpt best reflects which of the following ideas?

a) Imperial competition in the New World
b) Differences in goals for European colonies
c) Focus on trade with American Indians
d) Export of raw materials in Columbian Exchange