The answer would be -2! :)
The error of percentage is the amount of error over the original amount.
In this case it is 22/95 (not 22 over 77 because 77 is not the original amount they expected to sell.
22/95 = .2315 or 23.2% to the nearest tenth of a percent
Perhaps your teacher just wants 23% as an the approximate error.
Your answer is gonna be C. 4
Hope I helped :)