15.
In a certain code language,
A + B means βA is the son of Bβ,
A β B means βA is the wife of Bβ,
A Γ B means βA is the brother of Bβ and
A Γ· B means βA is the mother of Bβ.
Based on the above, if βP + Q Γ· R β T Γ Mβ, which of the following is true?