Utilize the input text as a context reference, choose the right relationship between beta cell and insulin from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

No new safety signals or data were presented at this year's ADA conference, but data was presented that confirmed the preservation and restoration of beta cell function as determined by C-peptide, which is a measure of a person's own insulin production.

Answer: product_or_material_produced