Which bearing type falls between C2 and C3 in terms of clearance?

The correct choice is a standard bearing, which indeed falls between C2 and C3 clearance designations. To understand this, it's essential to grasp what these terms signify.

Clearance in bearings is the space between the rolling elements and the raceways. The designations C2, C3, and standard apply to the internal clearance of the bearings. C2 indicates a smaller-than-normal clearance, while C3 designates a larger-than-normal clearance. A standard bearing has a nominal internal clearance that would naturally fit between these two designations. This means that while it doesn't offer the tighter clearance of a C2 or the looseness of a C3, it maintains a balance suitable for regular applications.

The other choices, such as C4 and C5 bearings, represent clearances that exceed the normal range even more than C3, which takes them outside the scenario posed in the question. A P4 bearing pertains to precision classes, focusing on tolerance and accuracy rather than clearance, thus making it irrelevant in this context. Thus, the selection of a standard bearing is aligned with the requirement for a type that comfortably fits between C2 and C3.