The correct answer is 3. This is the most likely diagnosis at this stage.

The exact cause of osteitis pubis is not fully understood, but it is believed to result from repeated stress or trauma to the pelvic area, commonly due to excessive strain on the pubic symphysis, leading to microtears and inflammation in the surrounding tissues. Osteitis pubis can be temporarily ruled out due to the findings from palpation.

The symptoms of a pelvic sprain may include:

1. Pain in the pelvic region, which may be sharp or dull.
2. Tenderness and swelling in the affected area.
3. Difficulty with weight-bearing activities, such as walking or standing.
4. Pain or discomfort with movements that involve the pelvis, such as bending, twisting, or lifting.
5. Bruising or discoloration around the injured area.
6. Limited range of motion or stiffness in the hips or lower back.

However, using correct stabilizing techniques, MMT is typically negative as no contractile tissues are usually involved. As before, the palpation findings of a defect over the mid-muscle belly of the adductor magnus on the involved side and evidence of significant ecchymosis in the same area also help to temporarily rule out a pelvic sprain.

The signs and symptoms of a femoral neck stress fracture include:

1. Pain in the groin or hip area that worsens with weight-bearing activities.
2. Pain that is relieved with rest.
3. Pain that may radiate to the knee.
4. Difficulty walking or limping.
5. Swelling or tenderness in the hip area.

Thus, given the mechanism of injury, the findings from the palpation and visual observation of the ecchymosis location tend to rule out a femoral neck stress fracture.