Changing, reversing, or omitting a small part in a routine incurs what penalty?

The correct choice indicates that changing, reversing, or omitting a small part of a routine incurs no penalty at all (0.0). In gymnastics judging, minor alterations that do not significantly impact the overall performance or intent of the routine are generally viewed as negligible, hence the absence of any deductions for such changes. This approach allows for flexibility and accommodates the natural variations that can occur during a performance without unduly penalizing the gymnast.

In contrast, the other options imply varying degrees of penalties that would be applied for deviations that are more significant than what is considered minor. For instance, a deduction might be warranted if the errors are deemed substantial enough to affect the quality or execution of the routine, but in the case of small adjustments, no penalty reflects a standard practice within the judging guidelines.