Which of the following is a pulsatile tumour?
Both osteoclastoma and telangiectatic osteosarcoma can present as pulsatile tumours. However, the best answer here is osteoclastoma, because, telangiectatic osteosarcoma is a less common variant of osteogenic sarcoma. Further, telangiectatic osteosarcoma can be pulsatile in very rare cases. So, the overall frequency is very less.

Pulsatile bone tumors

Giant cell tumor (osteoclastoma)
Telengiectatic osteosarcoma
Angiosarcoma/angioendothelioma of bone
Aneurysmal bone cyst
Secondaries from thyroid carcinoma and hypernephroma (renal cell carcinoma).
Osteosarcoma
Chondrosarcoma
Ewing's sarcoma
Osteoclastoma