Thorium induced tumor-

Ans. is 'a' i.e., Angiosarcoma of livero There is sufficient evidence for the carcinogenecity of thorium dioxide in humanso When administered by intravascular injection thorium dioxide has been reported to have induced numerous cases of malignant neoplasms.o Thorotrost (thorium dioxide) is commonly associated with liver neoplasm.o The most common liver neoplasm associated with thorium exposure :-Angiosarcoma of the liverCholangiocarcinomaHepatocellular carcinomao Other tumours that are associated with thorium exposure areCarcinomas and sarcomas of the renal pelvisLeukemiaOsteosarcomasAngiosarcomas of the livero Thorium dioxide is a radioactive heavy white crystalline powdero Thorium dioxide was used as a radiopaque medium for x-ray imaging in certain medical diagnostic procedures but was practically discarded after 1945 because carcinogenecity has been reported with thorotrost.