Assume somebody without a life labeled 6000 coins in the following manner: 1000 pennies from current circulation with whole numbers 0001 to 1000, 1000 nickels from current circulation with whole numbers 1001 to 2000. 1000 dimes from current circulation with whole numbers 2001 to 3000, 1000 quarters from current circulation with whole numbers 3001 to 4000, 1000 half-dollars from current circulation with whole numbers 4001 to 5000, and 1000 silver-dollars from current circulation with whole numbers 5001 to 6000. Identify the type of sampling used to generate the random sample described below. Group coins according to denomination (pennies, nickels, dimes, quarters, half-dollars, and silverdollars) and randomly select 10 coins from each group to form a sample of size 60. O stratified O systematic O simple random O cluster Omulti-stage