Answer:
C) temporary
Step-by-step explanation:
Farm Fresh's competitive advantage is based on organically raised chicken and beef, which has been great for them, but it is also something temporary because other restaurants can imitate them.
In the US, more than 19 million organic chicken are raised and consumed every year, and more than 50,000 organically-certified beef cows are herded (it takes more than a year for them to be consumed). Those numbers are growing year after year, and no one has a monopoly over their sale.
In order for a competitive advantage to be permanent and sustainable, it must be extremely difficult for other competitors to copy them, but it is not the case here.