What defines tenancy by the entireties?

Tenancy by the entireties is specifically a form of property ownership that can only occur between married couples. This type of ownership indicates that both spouses have an equal and undivided interest in the property. This means that neither spouse can sell or transfer their interest in the property without the consent of the other, which reinforces the idea of unity in ownership.

This arrangement provides certain protections, such as safeguarding the property from claims by creditors of one spouse alone, ensuring that both individuals have equal rights to the property during their marriage and, upon one spouse's death, the surviving spouse automatically retains full ownership. Therefore, option B correctly defines tenancy by the entireties as requiring both ownership from a married couple with no ability for either party to divide or separately control their interest in the property.