Data Sufficiency

Each baby born at a certain hospital last week was either a single birth or one of a pair twins. If x is the number of babies born at the hospital last week, is x odd?

i) 33 single births
ii) 3 pairs of twins born

At present I do not have OA. However, this question was one among others I answered wrong at a previous mock test at my Gmat school

My line of reasoning was the below:

S - > single births
T - > twin births
X - > Total babies

S + 2T = X

i) 33 + 2T = X, which can be translated odd + even = odd, so i is SUFFICIENT

ii) S + 2*3 = X, NOT SUFFICIENT

so answer must be A, correct?