What is an example of a motor muscle in meat?

The correct answer is rounds because it refers to a specific part of the beef that has a significant amount of muscle used for movement, which contributes to its designation as a motor muscle. This muscle generally comes from the hindquarters of the animal and includes muscles that are used for walking and standing, leading to a leaner cut compared to other portions. As a motor muscle, it is typically firmer and may require longer cooking times to become tender.

In contrast, options such as brisket, tenderloin, and ribeye represent different cuts of meat with varying characteristics. Brisket comes from the chest area and is known for its fat content, tenderloin is a very tender cut due to its location in the back of the animal and is not primarily a muscle for movement, and ribeye, while offering rich flavor due to its marbling, is also not classified as a motor muscle because it comes from a region that is less used during the animal's mobility. Thus, the selection of rounds accurately aligns with the definition of a motor muscle in meat.