Tunica albuginea is related to
a. Liver
b. Lung
c. Spleen
d. Testes

Hint: We are familiar that testes is the primary sex organ in males and they are situated outside the abdominal cavity within the scrotum which is a pouch like structure. The testes is enclosed by three defensive coatings with the term called tunica. Tunica albuginea is surrounded by fibrous tissues.

Complete answer:
 > Option(a) Liver- It consists of Visceral peritoneum, Glisson capsule, portal tracts etc. so this option is incorrect.

> Option (b) Lungs- Its layers are parietal pleura and visceral pleural and it has different parts like trachea, bronchi, bronchioles, alveoli, etc. so this option is also incorrect.

> Option (c) Spleen- It consists of fibrous tissues, lymphatic system, connective tissues, elastin fibers, etc. so this option is also incorrect.
Testes is enclosed in three defensive coatings known as tunica i.e. Tunica Vasculosa, Tunica Vaginalis, and Tunica Albuginea.
Here, Tunica vasculosa is a vascular layer which consists of blood vessels and it covers the inner surface of the tunica albuginea. Tunica vaginalis is a pouch like structure that covers the testes and it is the outermost layer. Tunica albuginea is the innermost layer and it is bi-layer structure which consists of an outer longitudinal and inner circular layer.
The tunica albuginea extends the length of the corpora cavernosa penis (i.e. containing erectile tissue). The tunica albuginea is involved in maintaining an erection.

Hence, the correct answer is option (D).

Note: Tunica albuginea is also present in the female reproductive system on the surface of ovaries. Spermatogenesis process takes place in the testes and spermatozoa requires less temperature than normal or body temperature. Tunica albuginea is a dense layer of tissues which connects the fibrous layer which surrounds the epididymis.