Which of the following is NOT an example of increased compensation due to higher risk?
a) Workers in the Mexican sex trade industry receive 23% higher wages for unprotected sexual acts.
b) Oil platform welders receive 33% higher compensation for working on rigs that drill in deeper waters, and at higher pressures, than others.
c) Airline pilots receive a 10% bonus for completing a month of on-time flights.
d) Freight boat captains earn 150% higher wages for shipping goods off the horn of Africa near Somalia, where a formal government has not existed for some time and piracy is rampant.