Final answer:
Georgia seceded from the Union prompted by the election of Abraham Lincoln as president, in anticipation of his opposition to slavery.
Step-by-step explanation:
The event that triggered Georgia's decision to secede from the Union was C) The election of Abraham Lincoln as president. The southern states seceded because they anticipated that Lincoln would challenge the institution of slavery, which was the foundation of their economic and social order. Following the lead of South Carolina, which seceded in December 1860, Georgia and other Deep South states seceded from the Union shortly thereafter.