Answer Happy

To encourage online sales, companies often try to attract
subscribers by offering them free gifts using an online "Spin the
Wheel". Suppose there are 9 possible types of free gifts in the
wheel. To check whether all the possible gift categories are
equally likely, i.e. the wheel is fair, the wheel is spinned 100
times and the number of counts of each type of gift is recorded.
What is the degrees of freedom of the chi squared test to assess
the claim of the fairness of the wheel?
a.) 99
b.)8
c.)10.
d.)9