Which phrase effectively uses "disappointed" in the context of low expectations?

The phrase that effectively uses "disappointed" in the context of low expectations is the one that states feeling disappointment regarding performance. When someone feels disappointed, it typically implies that there was a gap between what they hoped for or anticipated and what actually occurred. In this case, expressing disappointment about performance suggests that the individual had some expectations, albeit perhaps modest ones, which were not met.

The other phrases do not convey disappointment or imply low expectations. The statement about excitement indicates high hopes, while expressing confidence suggests a strong belief in a positive outcome. Lastly, feeling indifferent implies a lack of emotional investment or expectation, which contradicts the notion of being disappointed. Therefore, the first phrase accurately captures the sentiment of disappointment in relation to unmet expectations.