The correct answer is breakthrough.
A breakthrough is a significant and important advance in a particular area of knowledge or technology. In the context of the question, the new education policy provides a useful breakthrough for the planners to remove illiteracy. This is because the policy provides a number of new initiatives and reforms that are designed to improve access to education and quality of education, which will ultimately help to reduce the number of illiterate people in the country.
The other options are incorrect because they do not accurately reflect the meaning of the word “breakthrough”. A breakup is a separation or division into smaller parts, a breakaway is a sudden and decisive departure from a group or organization, and a break-in is an unauthorized entry into a building or other structure.