212. Most common primary malignant tumour of long bones is

a.Osteosarcoma
b.Multiple myeloma
c.Ewings sarcoma
d.Metastatic carcinoma

Ans:a.Osteosarcoma

Explanation:osteosarcoma is the commonest primary malignant tumour of long bones and Multiple myeloma is the commonest primary malignant tumour. (Ref robbins 7th ed)