**Core Concept**
Aspirin (acetylsalicylic acid) is a nonsteroidal anti-inflammatory drug (NSAID) that inhibits the production of prostaglandins, which are key mediators of inflammation and pain. This action is achieved through the inhibition of an enzyme responsible for the production of prostaglandins.

**Why the Correct Answer is Right**
Aspirin exerts its anti-inflammatory and analgesic effects by irreversibly inhibiting the enzyme cyclooxygenase (COX), specifically the COX-1 isoform. This inhibition prevents the conversion of arachidonic acid to prostaglandin H2 (PGH2), a crucial step in the production of prostaglandins. The inhibition of COX-1 also leads to a decrease in the production of thromboxane A2, a potent platelet aggregator.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the mechanism of action of aspirin.
**Option B:** This option is incorrect because it refers to a different class of drugs, such as beta-blockers, which work through a different mechanism.
**Option C:** This option is incorrect because it is a partial description of the mechanism, but it does not accurately represent the full picture of how aspirin works.

**Clinical Pearl / High-Yield Fact**
Aspirin's mechanism of action is unique in that it irreversibly inhibits COX-1, leading to a prolonged duration of action. This is in contrast to other NSAIDs, which may have a reversible or competitive inhibition of COX enzymes.

**Correct Answer: D. Inhibition of COX enzyme.**