Final answer:
The real cost of an ounce of marijuana in 1970, when adjusted for inflation to the year 2017, is approximately $55.60, which is not one of the given options.
Step-by-step explanation:
To calculate the real cost of an ounce of marijuana from 1970 in 2017 dollars, we need to adjust the price by the change in the price index, or the rate of inflation. Given that the price index was 15.5 in 1970, and knowing that $1 in 2017 has the same purchasing power as $0.18 in 1970, we can calculate the inflation multiplier by dividing 1 by 0.18 to get approximately 5.56. Therefore, the real cost of an ounce of marijuana in 2017 dollars would be $10 multiplied by 5.56, which equals approximately $55.60. None of the choices given are correct.