On a tree, there are some parrots and some pigeons in the ratio of 7 ∶ 9, respectively. After an hour, 8 parrots fly away, and 6 pigeons and 10 sparrows come and sit on the tree. The ratio of the parrots and the pigeons on the tree now is 1 ∶ 4. What is the ratio of the parrots and the sparrows that are now on the tree?
1
1 ∶ 1
2
1 ∶ 2
3
3 ∶ 5
4
4 ∶ 5