Question

Inorganic fertiliser is applied each year to fields bordering a lake. the fertiliser runs off into the lake and causes six changes which altogether make the fish die.

1. aerobic bacteria feed on dead plants
2. algae reproduce faster
3. light cannot penetrate water
4. oxygen levels fall
5. water becomes green
6. underwater plants die

In which order do the changes take place?

My answer: 2,5,3,6,1,4

But the answer provided by the book says: 2,5,1,6,4,3

Am i wrong?