Don Juan Perez runs a seafood restaurant. His total income last year was $150,000. The rent was US$48,000 per year. His labour costs were $42,000 and materials, food and other variable costs were...

Don Juan Perez runs a seafood restaurant. His total income last year was $150,000. The rent was US$48,000 per year. His labour costs were $42,000 and materials, food and other variable costs were $20,000. Don Juan Perez was going to write a cookbook where he would have earned $40,000 per year, or as a chef de cuisine in another restaurant, where he would have earned $35,000. The economic utility of Don Juan Perez is:
(a) 0 (zero) per year
b) 5,000 dollars a year
c) -$35,000 per year
d) $40,000 per year