Utilize the input text as a context reference, choose the right relationship between 'Cigna' and 'health insurance' from the options.
Options: product/material produced, subsidiary, platform, location of formation

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