A 2710 G Mixture Contains CaCl₂ - Which Does Not React

Multiple Choice

A 2.710 g mixture contains CaCl₂ - which does not react with HCl(aq) - and also CaO, which does react:
CaO(s) + 2HCl(aq) $\rarr$ CaCl₂ (aq) + H₂O(l) .
It took 32.05 mL of 2.445 M HCl(aq) to react completely with all the CaO in the sample. The percent, by weight, of CaO in the sample is Hint: Work backwards once you determine the amount of CaO present.

A) 35.15 %
B) 61.67 %
C) 77.62 %
D) 81.08 %
E) 84.17 %