After Taking a Random Start Between 1 and 20 and Then

After taking a random start between 1 and 20 and then taking every 20th element from the sampling frame,Smith learned that 40% of the sample believed the company's president was doing a good job.The calculated standard error was 3 percent.Assuming a normal distribution,this means that

A) between 37% and 43% of the employees believe the president is doing a good job.
B) you are 95% certain that between 37% and 43% of the employees believe the president is doing a good job.
C) you are 68% certain that between 37% and 43% of the employees believe the president is doing a good job.
D) you are 99% certain that between 37% and 43% of the employees believe the president is doing a good job.
E) between one and twenty percent of the sample believes the president is doing a good job.