In early 1973, which two substances were produced at the same manufacturing plant and resulted in PBB being shipped to Michigan Farm Bureau Services?

• A. PBB and DDT
• B. PBB and Magnesium Oxide
• C. PBB and Formaldehyde
• D. PBB only

Answer: (B)

This question tests understanding of how cross-contamination can happen when more than one substance is produced at the same facility. In early 1973, a plant that was manufacturing both PBB (a flame retardant) and magnesium oxide mishandled production or labeling, resulting in PBB being shipped to Michigan Farm Bureau Services instead of the intended magnesium oxide product. Because these two substances came from the same site, the PBB ended up in the supply chain, contaminating a product that was supposed to be magnesium oxide. This scenario fits the historical event where two substances were produced at the same plant and led to PBB being distributed to Michigan Farm Bureau Services. The other options do not reflect that specific incident, which is why this pairing is the best choice.