Answer:
A). by sending unarmed supply ships to the fort.
Step-by-step explanation:
Lincoln tried to calmly resolve the question of resupply to the Fort of Sumter by 'dispatching unguarded supply ships to the fort.' He knew that the location of Sumter fort was very vital as it safeguarded the southern coast's trade locations and thus, he was extremely tensed regarding the resupply to the fort because he didn't wish to succumb to the conspiracies made against it by the federation. The Fort existed within the union and thus, they want to take its authority and this eventually led to the beginning of the civil war. Hence, option A is the correct answer.