Which of the following medications is commonly used as a blood thinner?

Aspirin is commonly used as a blood thinner due to its antiplatelet properties, which help prevent blood clots. It works by inhibiting the function of platelets in the blood, reducing their ability to clump together. This property makes aspirin effective in reducing the risk of heart attacks and strokes in individuals with certain cardiovascular conditions.

In contrast, ibuprofen and ketorolac are nonsteroidal anti-inflammatory drugs (NSAIDs) that can also affect blood clotting but primarily serve pain relief and anti-inflammatory purposes. Lorazepam is a benzodiazepine used primarily for anxiety and does not have any blood-thinning effects. Therefore, among the options provided, aspirin is the medication that is specifically recognized for its role in thinning the blood and preventing clot formation.