The correct answer is A) By opening a second front at Mobile, de Gálvez prevented the British from sending additional troops to Pensacola.
The statement that explains how the actions of Bernardo de Gálvez affected British troops in Florida is "By opening a second front at Mobile, de Gálvez prevented the British from sending additional troops to Pensacola."
Spaniard Bernardo de Gálvex was the prominent figure in the Battle of Pensacola that was fought from March 9 to May 8, 1781, in the territory known at that time as British West Florida.
Gálvez was the Spanish governor of Louisiana and decided to confront the British troops and he led the troops that resulted victoriously. By defeating the English troops, the British had to leave Florida to the Spaniards.