Which of the following quantifiers suggests a lower level of confidence?

The choice suggesting a lower level of confidence is based on the inherent meaning of the quantifiers used. "A significant percentage" indicates that a considerable part of a group or population meets a certain criterion, yet it does not provide a strong assurance about the majority or near-totality of that group. This term implies some uncertainty, as "significant" is a relative term and does not specify how many people or instances are included.

In contrast, options such as "almost all," "most likely," and "highly probable" convey stronger levels of confidence. "Almost all" suggests a very high degree of certainty, while "most likely" and "highly probable" imply a strong expectation of an outcome. Therefore, "a significant percentage" aligns with the idea of a lower level of confidence compared to the other options, as it indicates less definitive information about the extent of agreement or occurrence.