'A $$\times$$ B' means 'A is the father of B'
'A $$+$$ B' means 'A is the mother of B'
'A $$\div$$ B' means 'A is the son of B'
'A $$-$$ B' means 'A is the daughter of B'
How is A related to D in the expression '$$A \div B + C \times D$$'?

A

Brother

B

Father

C

Son

D

Father's brother