A zoologist is studying four very closely related feline species. She wishes to compare their gestation periods. An observational study is conducted where the zoologist observes the gestation period of 50 randomly selected felines in each species. A one-way ANOVA test is run to test the hypothesis that the average gestation period is the same for each of the four species. A level of significance of 0.05 is used, and a P-value of 0.01 is calculated. Based on this result, the conclusion that can be drawn is that:

a. all of the average gestation periods are the same across all four species
b. at least some, but not all, of the gestation periods across all four species are the same
c. all of the average gestation periods across all four species are different
d. not all of the average gestation periods are the same across all four species