That seems like a very complicated question to try and answer without some background information about the situation eg. the type of person the woman is, the relationship between the couple, the circumstances of the proposal. . . . I mean so many things could be factors in the deafening silence that might make a man who has proposed wish that the earth would swallow him up right then and there. But I am making the assumption that most men propose with the intention of being answered with a "yes"
I think women are a mystery to men. And vice versa. But women especially seem to carry an image of being unpredictable. That's been my experience at least but I think it's part of our irresistible charm. So, in answer to your question without writing a novel, I would like to offer a highly philosophical final answer.
The most likely answer would be either of the two options with a third or fourth option tossed in there too. The reason I say this is because the only person who can say with absolute certainty what the answer will be is the woman who is asked the question. Conjecture could revolve for hours as to what is the most probable outcome but only one person involved has that knowledge and even then she might very well change her mind an hour before the wedding or an hour after the acceptance of the proposal! As my favorite saying goes, "C'est la vie baby!"