Take context from the input text and decide on the accurate relationship between 'Airbus' and 'aircraft' from the options provided.
Options: product/material produced, developer, employer, position held

Boeing has gained invaluable technical knowledge required to design, produce and certify commercial aircraft and operates in what is essentially a market duopoly with rival Airbus for the industry's bread-and-butter single and twin-aisle commercial aircraft segment.
product/material produced