A medical researcher wishes to compare the tissue damageproduced by slow neutrons, which have a relative biologicaleffectiveness (RBE) of 2.2, to that produced by fast neutrons withan RBE of 8.8. For the slow neutrons, the absorbed dose is 560 rd. What absorbed dose (in rd) of fast neutrons will produce the same biologically equivalent dose (in rem) as that for the slowneutrons?

a. 29 rd
b. 2240 rd
c. 310 rd
d. 140 rd
e. 560 rd