Which of the choices below is not a mechanism of heat transfer used by the body?

just finished the test, the answer is d, greg is the least cost-effective because he charges the most for the project

answeramino acids;

energy per photon is e = h*c / λ  

e = 6.63*10^-34 * 3*10^8 / 6*10^-7 j = 3.315*10^-19 j  

nr. of photons = 10j / 3.315*10 = ^-19 j per photon = 3.02*10^19 photons

what is the question?