Take context from the input text and decide on the accurate relationship between 'Cigna' and 'health insurance' from the options provided.
Options: location of formation, platform, subsidiary, product/material produced

Insurer Anthem sealed a $54.2 billion deal to buy rival Cigna (NYSE: CI - news ) , in a further consolidation of the US health insurance industry in the wake of the US Affordable Care Act.
product/material produced