What if the Iranian Government does not accept the incentive package?

Last week, in a very brief meeting with reporters after the Security Council meeting on Zimbawe, Secretary of State, Condoliza Rice responded a few questions and didn't respond a few others, including my question. " What if the Iranian government does not accept the European incentive package? What will be the United States' stance on it?", I asked her. She said that she was going to talk about Zimbabwe, not the other things...Still, the question is on the table...more sanctions? more political pressure? military option? ...?