A Graduate Student of the College Conducted the Following Research

Multiple Choice

A graduate student of the college conducted the following research. She considered four consulting companies and selected 13-15 approximately similar vacancies in each of these companies, which were posted on the official websites during the last year. The student was interested in the information about the wages indicated in the vacancies. Assume that you know that the student decided to conduct an F-test to compare the interested values, and draw the null hypothesis for this test in plain English.
​

A) The null hypothesis is that the average wages in all consulting companies for a position of interest are equal.
B) The null hypothesis is that the average wages in the four companies considered are equal.
C) The null hypothesis is that the average wages in the four samples of vacancies for a position of interest are equal.
D) The null hypothesis is that the average wages in the four companies considered for a position of interest are equal.