Physiology Most of the testosterone secreted by the testes exists in the plasma in the form of ? A Dihydrotestosterone bound to gonadal steroid-binding hormone B Free dihydrotestosterone C Free testosterone D Testosterone bound to sex-steroid-binding globulin 💡 Explanation Most of the testosterone secreted by the testes exists in the plasma in the form of ? ✓ Correct Answer: D. Testosterone bound to sex-steroid-binding globulin