A Real Estate Company Is Analyzing the Selling Prices of Residential

A real estate company is analyzing the selling prices of residential homes in a given community. 140 homes that have been sold in the past month are randomly selected and their selling prices are recorded. The statistician working on the project has stated that in order to perform various statistical tests, the data must be distributed according to a normal distribution. In order to determine whether the selling prices of homes included in the random sample are normally distributed, the statistician divides the data into 6 classes of equal size and records the number of observations in each class. She then performs a chi-square goodness-of-fit test for normal distribution. The results are summarized in the following table Goodness-of-Fit Test
What are the degrees of freedom for the chi-square test?

A) 2
B) 3
C) 4
D) 5
E) 6