Which claim type is not allowed in a utility application?

In a utility application, a dependent claim must refer to a previously stated independent claim to establish its context and scope. Therefore, a dependent claim without an independent base lacks the necessary foundation to be valid. It does not properly define its subject matter based on an earlier claim, which is a requirement in patent law to ensure clarity and enablement.

In contrast, a single independent claim is perfectly acceptable as it can stand alone, asserting its own distinct inventive concept. Multiple independent claims can also be included in a utility application, provided the application meets the requirements of unity of invention. However, a claim with multiple dependencies may raise concerns about clarity but can still be considered under certain conditions, so long as it adheres to the rules of claim structure. Thus, the absence of an independent base renders a dependent claim invalid in a utility application setting, which makes it the correct choice for this question.