Dosage help for practice test, my answer is not A, B, C, or D,

ok guys help me out, i was taking a practice dosage test for my ce for work. the question was this, i worked the problem like this and my answer wasn't a choice. what gives? i even went and looked up in several dosage / meds books and still got the same thing help !!

drug is xyb immunization

15mg/kg vial is 50mg/0.5ml

pt weighs 10.9lbs how much would you give?

simple 10.9 / 2.2 = 4.95 round to 5 kg

15mg/kg x 5kg= 75mg

5omg/0.5ml / 75mg= 1.5mg

1.5 x 0.5 = 0.75ml

so give 0.75ml

there answers to chose from were

a. 0.66 ml

b. 3ml

c. 0.075ml

d. 0.5 ml

sorry this is so long, but it is driving me nuts and i have to take the real test on monday. i just hope there isn't a very similar question liek this.

i am thinking answer c was a typo error.

any all help is greatly appreciated!

also, i had a test question like this on another meds test several years age and the exact one was on the real test, except the real test had the typo not the practice test. the error wasn't caught unitl too many people complained . that test was almost question per question as the practice test they gave us to practice with.

again thanks all!!