It . . . . . . . . to me that she was incurable.

The correct answer is suggested.

• Happened means to take place by chance or accident. It does not make sense to say that something “happened” to someone, as if it were an event that was beyond their control.
• Occurred means to take place or come into being. It is a more formal word than “happened,” but it does not have the same negative connotation.
• Flashed means to appear suddenly and disappear quickly. It does not make sense to say that something “flashed” to someone, as if it were a fleeting thought or image.
• Suggested means to put forward an idea or proposal. It is the most appropriate word in this context, as it suggests that the speaker was considering the possibility that the woman was incurable.

In the sentence “It suggested to me that she was incurable,” the word “suggested” is used in the sense of “to put forward an idea or proposal.” The speaker is considering the possibility that the woman is incurable, and is not stating it as a fact.