In particular, they have leapt more than 80 percent since October, when CEO Sergio Marchionne announced plans to spin off Ferrari and give a big chunk of the highly-prized sports car maker's shares to Fiat Chrysler Automobiles (FCA) investors.
Analyze the relationship between 'Sergio Marchionne' and 'Fiat' within the context of the input sentence.
Options: legal form, employer, platform, headquarters location