If K ÷ L means that K is the mother of L, K – L means that K is the father of L, K × L means that K is the sister of L, then which of the following expression shows that P is the paternal grandmother of R?
1
P ÷ Q × R
2
R – Q ÷ P
3
P ÷ Q – R
4
Q ÷ P – R