I don't understand this chemistry question!?

Question

put 3.27 micrograms of C2H3Cl3 into moles.
a) .0245 mol
b) .0675 mol
c) 2.45E-8 mol
d) 6.75E-8 mol
e) 2.45E3 mol

I worked out the problem numerous times, but still couldn't come up with an answer that was available. Can someone walk me through it!?! thanks

Answer 1

microgram is 10^-6, so this is 327 * 10^-8 g

divide by the molar mass, (133.35 g/mol) = 2.45 E-8 mol
CHOICE C

Answer 2

Atomic weights: C=12 H=1 Cl=35.5 C2H3Cl3=133.5

3.27 x 10^-6g x 1molC2H3Cl3/133.5C2H3Cl3 = 2.45 x 10^-8 mole

c) is correct.

Answer 3

133.42 g/mol, so 3.27 micrograms equals .000000327 grams, so .00000327/133.42=2.45*10-8