Answer: d) spending on imports
Explanation: In economic terms, injections are additions to the economy that stimulate growth and increase aggregate demand. These include investments made by businesses, government spending on public goods and services, and exports, which bring money into the economy from foreign buyers. On the other hand, spending on imports represents money flowing out of the economy as purchases are made from foreign producers. Therefore, while it involves spending, it does not serve as an injection and is considered a leakage from the economy, so the correct answer is d) spending on imports.