**Core Concept**
Rhabdomyosarcoma of the orbit is a type of soft tissue sarcoma that originates from skeletal muscle cells. The histological classification of rhabdomyosarcoma is essential for determining the prognosis and treatment plan.

**Why the Correct Answer is Right**
The correct answer is Embryonal Rhabdomyosarcoma. This type accounts for approximately 60-70% of orbital rhabdomyosarcomas. Embryonal rhabdomyosarcoma is characterized by the presence of small, round, blue cells with a high mitotic rate and minimal differentiation towards skeletal muscle cells. The embryonal subtype is more common in children and tends to have a better prognosis compared to the alveolar subtype.

**Why Each Wrong Option is Incorrect**
* **Option A:** Alveolar Rhabdomyosarcoma is a more aggressive subtype with a poorer prognosis, but it is less common in the orbit compared to Embryonal Rhabdomyosarcoma.
* **Option B:** Botryoid Rhabdomyosarcoma is a subtype that typically presents in the genitourinary tract, particularly in the bladder and vagina, and is less common in the orbit.
* **Option C:** Pleomorphic Rhabdomyosarcoma is the most common adult type, but it is less common in the orbit compared to Embryonal Rhabdomyosarcoma.

**Clinical Pearl / High-Yield Fact**
Embryonal Rhabdomyosarcoma of the orbit often presents with symptoms such as proptosis, ptosis, and diplopia. A high index of suspicion is required for early diagnosis and treatment to prevent orbital invasion and improve visual outcomes.

**Correct Answer:** C.