Question

which of the following can be damaged by radiation waves outside the body? only cancerous cells the cardiovascular system the dna structure of the tumor

Explanation:

• Option "only cancerous cells": Radiation (like in radiation therapy) can affect both cancerous and healthy cells, so this is incorrect.
• Option "the cardiovascular system": While radiation can have long - term effects on the cardiovascular system, the primary direct target of radiation waves (especially in the context of tumor treatment) is the DNA of cells. Also, the question is about what can be damaged by radiation waves outside the body (implying a more direct cellular - level damage related to tumors), so this is not the best answer.
• Option "the DNA structure of the tumor": Radiation (such as ionizing radiation) can cause breaks in the DNA structure of cells, including tumor cells. This is a well - known mechanism of how radiation is used to treat cancer (by damaging the DNA of cancer cells to prevent them from dividing) and also how external radiation can damage the DNA of tumor cells.

Answer:

the DNA structure of the tumor