In a lottery, numbered balls from 1 through 69 are placed into a spinning drum. Every 10 seconds a ball rolls down a tube to become one of the eight numbers to be drawn. At the end of the draw, the remaining 61 balls have an equally likely chance of becoming the bonus number. What is the name of this method of sampling?1. Simple random sampling
2. Systematic random sampling
3. Stratified random sampling
4. Convenience sampling