Which variable expression matches the word phrase?

1.
the sum of 12 and the quotient of 9 and a number

2.
the difference of 12 and the product of 9 and a number

3.
the difference of 12 and the quotient of 9 and a number

4.
12 more than quotient of a 9 and number

a.
12 + (9 ÷ y)

b.
12 – (9 ÷ y)

c.
12 – 9y me