What tone did she use when she stated there would be no difficulties?

The answer highlights a tone that conveys assurance and a sense of certainty. When someone states that there will be no difficulties, it suggests a positive outlook and a belief in the smoothness of the situation ahead. This confident and reassuring demeanor is aimed at alleviating any concerns or anxieties, instilling a sense of trust in the speaker's assessment of the situation.

In contrast, the other tones represented by the remaining options reflect negative or indifferent attitudes, which would not align with a statement that implies ease and lack of problems. The correct choice showcases a proactive and supportive communication style, indicating an optimistic perspective on upcoming events or challenges.