NBME question ,,, help

hey everyone .. here is a question , seems very easy but the answer in offline key is wired everywhere .. kindly help
50year old with fever and shaking chills for 24 hoours, 1 week before tread by
a 5-FU for a tumor, on labs , counts WBC=400/mm3 platelet=1oo,ooo/mm3 and haemocrit 30 ..
which of the following should be best combined with drug

1) erythropoitin
2 GM-CSF
3) IL-1
4)IL_1
5) leucoverin

please help on this