On a recent visit to New York City, Sam made a list of 200 museums, cultural institutions, and historic sites that he would like to visit on a single sheet of paper. He only had time to visit four of these places and decided to use the method of systematic random sampling to select the four places to visit.
Determine which method best describes a systematic random sample?

a. Sam assigns a number from 1 to 200 to each place on his list. Next, he uses a random number generator to generate four random numbers between 1 and 200. He uses the numbers that are generated to choose the four places he will visit.
b. Sam divides New York City into ten geographical regions, each containing more than four places. He uses a random number generator to select one region. He then uses the random number generator again to select four places in that region.
c. Sam assigns a number from 1 to 200 to each place. Next, he uses a random number generator to choose a number between 1 and 50. He chooses that place and every fiftieth place after that until he has chosen a total of four.
d. Sam sorts the list of places into four categories (art, education, entertainment, and other) and selects one place at random from each category to obtain his list of four places to visit.