The claim that PBfit has a definite expiration date is a matter of common knowledge regarding packaged food products, which universally carry expiration or best-by dates for quality and safety, requiring no formal scientific citation.
The claim concerns the presence of an expiration date on a commercial food product (PBfit, a peanut butter powder). All packaged foods are legally and practically required to carry expiration or best-by dates. Therefore, this is common knowledge that requires no citation, and Step 0 designates it as COMMON_KNOWLEDGE.