mode of heat transfer by a body

Question

Suppose the mean body surface temperature of a certain unclothed person is 30⁰C the mean temperature of surrounding surfaces is 21⁰C and the air within the room is at 32⁰C, 90% RH, then the person will lose maximum body heat by

(a) Convection 

(b) radiation

(c) Mass – transfer

(d) Convection radiation and mass – transfer