This cavity is inferior to the abdominal

Pelvic Cavity.

Explanation:

The pelvic cavity is funnel-shaped and is located inferior and anterior to the abdominal cavity. Abdominopelvic cavity–the abdominal cavity and the pelvic cavity in combination. Abdominal cavity–the space occupied by the ventral internal organs inferior to the diaphragm and superior to the pelvic cavity.

Hope this helps.

"d.) carbon dioxide and hydrogen sulfide"

that is wrong, its not thymus.