An inmate escapes from the county prison. There is a $500 reward offered for any information leading to the capture of the inmate. The county sheriff sees the inmate at a local restaurant and calls the department headquarters before arresting the inmate. The sheriff:
a. can expect to collect the $500 because he called the department headquarters before arresting the inmate.
b. cannot expect to collect the $500 because he had a preexisting duty to arrest the inmate.
c. can expect to collect the $500 because he performed a civil service.
d. cannot expect to collect the $500 because of the doctrine of unforeseen difficulties.