Answer:
d. Spain's support of the American Revolution
Step-by-step explanation:
Bernardo de Gálvez was widely known under the Spanish rule of Louisiana to be the 5th Governor. During his campaign as the Governor of the Louisiana region, particularly during the American Revolution war, he was known to have supported American Colonies, against the British. Also, he fought the British armies at the Siege of Pensacola, thereby gaining the western part of Florida from the British.
Hence, the right answer is that the Galvez campaign illustrated "Spain's support of the American Revolution."