The population of rats in a locality increases by 20% in one year.Observing this, the pest control committee decided to use a special kind of pesticide `xyz' which effectively kills 160 rats in 3 months. Just after 2 years, what is the net increase or decrease in the population of rats if, initially the population of rats is 3200 and pesticide is used effectively?

• A. Increase of 128 rats
• B. Decrease of 128 rats.
• C. Neither an increase nor a decrease in the population
• D. None of these