When you're in an interview you have to demonstrate genuine passion for the job you seek -- and a fervent desire to work in the related field long-term.
Uncertainty or vagueness about what you want to do in the future -- often accompanied by language such as "I'm not sure" or "I'm exploring a range of opportunities" -- will not serve you well in terms of selling an employer on your desire for a position.
Granted, you may not be certain about the job -- so "act as if" you want it. Muster all your enthusiasm and energy when you apply and interview for the position, so that there's no doubt in the employer's mind that you want the job.
I share these thoughts based on feedback I've received from some employers about USF MBA students communicating such uncertainty during job interviews, which ruled them out for further consideration.
In short, show you care deeply about the field and desire the position -- or else reconsider whether or not to apply, much less to go on the interview at all (should you be fortunate enough to be asked in for one).