In a certain code language,
A + B means 'A is the brother of B',
A - B means 'A is the father of B',
A × B means 'A is the mother of B',
A ÷ B means 'A is the wife of B'.
Based on the above, if 'P × Q - R ÷ S + T', which of the following is true?
1
T is the brother of R.
2
P is the mother of R.
3
T is the sister of S.
4
Q is the son of P.