Incorrect. An abscess forms when there is an infection that cannot drain to the surface. The pressure within and the surrounding inflammation typically make these painful and the patient reported the mass was pain free.

Incorrect. An inguinal hernia typically presents as a mass/lump at or just above the inguinal ligament, not inferiorly into the thigh.   

Unlikely. The apparent size of the mass is quite large and has expanded over just one month. Tumor growth of this rate would be quite unusual.

Correct! A lump emerging and extending inferiorly onto the thigh is mostly likely a femoral hernia. Patients with a uterus have overall lower hernia rates to individuals with testes, but relatively are more likely to develop femoral over inguinal hernia. The structure of the spermatic cord makes inguinal hernias more likely in individuals with testes. 

Incorrect. A hematoma from vascular injury would likely grow much faster than over a one month time frame. Also, there would likely be tenderness from bleeding into the subcutaneous tissue.