I would say, that depends on the definition of 'honest'. What does your textbook say about that?
But I would choose Ho: V=12 and H1: V<12, where V is the volume of soda per can.
Rationale: Null hypothesis is the 'status quo'; H1 hypothesis is challenging the status quo (in this case, with the results of the test).
V is the parameter of a distribution. 11.83 is the sample mean of the test which helps us to evaluate the parameter, or, in this case, to test the hypothesis relating to the parameter V.