Which structure is NOT associated with the external abdominal oblique muscle?

The external abdominal oblique muscle has a specific origin and insertion pattern that is key to its function in trunk movement and stability. This muscle originates from the external surfaces of the lower eight ribs (the first choice), which allows it to contribute significantly to lateral flexion and rotation of the trunk. As for its insertion, it connects to the linea alba and the iliac crest, allowing for stabilizing effects on the pelvis and spine.

The option discussing the support for the rectus abdominis highlights the role of the external oblique in maintaining abdominal pressure and stability in the abdominal wall, further emphasizing its importance in core support.

However, the origin at the crest and ramus of the pubis does not pertain to the external abdominal oblique muscle. This area is more relevant to the inguinal ligament and other structures associated with different muscles, such as the internal oblique and transversus abdominis, which originate from the pubis region instead. Thus, this particular structure does not align with the specific anatomy related to the external abdominal oblique, making it the correct choice in this context.