According to the Centers for Disease Control and Prevention (CDC), most unintentional nonfatal poisonings of children occur as a result of a child's ingestion of:

Unintentional nonfatal poisonings in children are often linked to the ingestion of medications, which is why the option regarding prescription or over-the-counter medication is the correct choice. Children are naturally curious and may easily mistake these medications for candy or other consumable items due to their colorful packaging and sometimes sweet taste.

The CDC has noted that pediatric poisoning incidents frequently involve either a child accessing a caregiver's medication or mistakenly taking medications that are left unsecured. This highlights the need for vigilant storage practices and supervision around medications to prevent such incidents.

Household cleaning products and plant materials can also pose risks, but they do not account for the majority of unintentional poisonings in children compared to medications. Food additives, while potentially harmful in excessive amounts, are less frequently responsible for nonfatal poisonings in young children. This context reinforces the critical focus on the safe handling and storage of medications in households with children.