**Core Concept**
Germ cell tumours of the testis originate from the germ cells, which are the cells that give rise to sperm. These tumours can be benign or malignant and are classified into several types based on their histological characteristics. The most common types of germ cell tumours include seminomas and non-seminomas.

**Why the Correct Answer is Right**
Seminomas are a type of germ cell tumour that account for about half of all testicular germ cell tumours. They are typically homogeneous and composed of large, rounded cells with distinct cell borders and clear cytoplasm. Teratomas are another type of germ cell tumour that can contain several different types of tissues, including hair, muscle, and bone.

**Why Each Wrong Option is Incorrect**
**Option C:** Leydig cell tumours are sex cord-stromal tumours, not germ cell tumours, and arise from the Leydig cells of the testis.
**Option D:** Gynandroblastoma is a rare type of sex cord-stromal tumour.
**Option E:** Rhabdomyoma is a type of benign muscle tumour.

**Clinical Pearl / High-Yield Fact**
It's essential to distinguish between seminomas and non-seminomas, as they have different treatment approaches and prognoses. Seminomas are highly sensitive to radiation and have a better prognosis than non-seminomas.

**Correct Answer:** A, B. Seminoma, Teratoma