Answer:
d. all of the above
Step-by-step explanation:
The three are cultural symbols of Oklahoma.
The historic Route 66 rans through the middle of the state, including the city of Tulsa, the second-largest in the state.
American Indian heritage is also important in Oklahoma. The entirety of Oklahoma used to be Indian reservation territory, and there are still important Indian reservations there.
Finally, cowboy culture is also remarkable. Oklahoma has been a state with an important livestock sector economy, and cowboys used to be employed en masse in the nineteenth century and early twentieth century.