Which of the following is a common disqualification for a rabbit in competition?

Overweight is a common disqualification for a rabbit in competition because it directly impacts the animal's health and performance. In competitive rabbit shows, each breed has a specific standard that includes ideal weight ranges. Rabbits that are overweight can both be disadvantaged in terms of movement and can also be perceived as poorly managed or less healthy by judges. Maintaining an appropriate weight is crucial not only for the rabbit’s well-being but also for meeting competitive standards.

In contrast, while light fur color, bite marks, and unusual ear shape might be points of consideration, they do not universally lead to disqualification across all breeds or shows. For instance, certain breeds may accept variations in fur color, and while cosmetic issues like bite marks can affect a rabbit's appearance, they are not always grounds for disqualification unless they indicate greater health issues. Similarly, unusual ear shape may be a fault, but it would only lead to disqualification if it explicitly contradicts the breed standard.