Final Answer:
The probability that your tax return was not selected for an audit in 2013 is 0.987 (Option A).
Step-by-step explanation:
Total number of tax returns audited: 1,242,479
Total number of individual tax returns (assuming one per person): 1
Probability of not being audited: (Total not audited / Total possible) = (Total possible - Total audited) / Total possible
Probability of not being audited: (1 - 1,242,479 / 1,242,480) = 0.999999195
Rounding to three decimal places: 0.999
Thus, the probability of not being audited is 0.999, which is closest to 0.987 (Option A).