Use the passage to answer the question.
RNAi has been proposed as a possible way to treat breast cancer and reduce the growth of tumor cells. Which of the following is a possible mechanism for how RNAi could prevent the growth of tumor cells by reducing the concentration of Ets1 in the cells?
Short segments of DNA that are complementary to the mRNA that codes for transcription factors such as Ets1 could be introduced into the tumor cells. This would prevent transcription of the gene that codes for Ets1 and therefore reduce its concentration in the cell.
Repressor proteins can be introduced into the tumor cells. These would bind Ets1 and prevent it from initiating transcription of growth-promoting genes.
Short segments of RNA that are complementary to the mRNA that codes for transcription factors such as Ets1 could be introduced into the tumor cells. This would cause the mRNA to be degraded before translation could occur, preventing the synthesis of Ets1.
Viral vectors can be used to introduce new genes that will cause the cell to undergo programmed cell death.