Explanation

Purchasing construction equipment (Option C) is least likely to create a sustainable increase in economic growth because:

• Building a new university (Option A) represents investment in human capital, which enhances labor productivity and creates long-term sustainable growth through education and innovation.
• Improving the electrical grid (Option B) represents infrastructure investment that enhances productivity across multiple sectors of the economy, creating sustainable growth through improved efficiency.
• Purchasing construction equipment (Option C) is primarily a capital investment that may boost short-term construction activity but doesn't fundamentally enhance the economy's productive capacity in a sustainable way. It represents investment in physical capital without necessarily improving technology, human capital, or infrastructure that drives long-term growth.

Sustainable economic growth typically comes from investments in human capital, technology, and infrastructure that increase the economy's productive capacity over the long term.