**Core Concept**
The management of malignant ovarian germ cell tumours involves a multidisciplinary approach, considering the stage and type of tumour. In stage IA, the cancer is limited to one ovary, with no ascites or tumour on the external surface, and no capsule rupture. **Surgery** and **chemotherapy** are key components of treatment.

**Why the Correct Answer is Right**
For stage IA malignant ovarian germ cell tumours, the standard treatment typically involves **surgical staging** followed by **adjuvant chemotherapy**. This approach aims to remove the tumour and affected ovary while minimizing the risk of recurrence.

**Why Each Wrong Option is Incorrect**
**Option A:** Inadequate for a malignant condition.
**Option B:** Not the standard for stage IA.
**Option D:** Too aggressive for early-stage disease.

**Clinical Pearl / High-Yield Fact**
In early-stage malignant ovarian germ cell tumours, **fertility-sparing surgery** may be considered, especially in young patients wishing to preserve reproductive function.

**Correct Answer:** D. Surgery followed by chemotherapy.