4. Determine whether each of the following arrangements is an option. If so, decide whether it is a call or a put and identify the premium.

a. You purchase homeowner's insurance for your house.

b. You are a high school senior evaluating possible college choices. One school promises that if you enroll, it will guarantee your tuition rate for the next four years.

c. You enter into a noncancelable, long-term apartment lease.