Which of the following policies would likely not promote economic growth? Replacing old snow plows with new state-of-the-art snow plows.

Offering after-work computer enhancement classes.

Awarding scholarships to bright high school students.

Reducing the number of student visas issued to international students.

Investment in superior capital equipment increases economic efficiency, which fosters economic growth.
Offering after work classes would promote education, which increases the level of human capital, fostering economic growth.
Education increases the level of human capital, which fosters economic growth. Thus awarding scholarships to bright high school students would promote economic growth.
Therefore the answer is reducing the number of student visas issued to international students.