**Core Concept**
Quinolone antibiotics are a class of broad-spectrum antibacterial agents that act by inhibiting bacterial DNA gyrase and topoisomerase IV, essential enzymes for DNA replication and transcription. These agents exhibit a broad spectrum of activity against both Gram-negative and Gram-positive bacteria.

**Why the Correct Answer is Right**
The correct answer is a quinolone antibiotic that effectively targets both Gram-negative and Gram-positive bacteria. It achieves this by inhibiting DNA gyrase and topoisomerase IV, two critical enzymes involved in bacterial DNA replication and transcription. The mechanism of action of this antibiotic involves the inhibition of DNA supercoiling, which ultimately leads to the induction of DNA strand breaks and the inhibition of bacterial growth.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it is a different class of antibiotics, such as beta-lactams (e.g., penicillins, cephalosporins), which have a narrower spectrum of activity and primarily target Gram-positive bacteria.

**Option B:** This option is incorrect as it refers to a different class of antibiotics, such as sulfonamides, which are primarily bacteriostatic and have a narrower spectrum of activity.

**Option C:** This option is incorrect as it refers to a different class of antibiotics, such as macrolides, which have a narrower spectrum of activity and primarily target Gram-positive bacteria.

**Clinical Pearl / High-Yield Fact**
Quinolone antibiotics are a broad-spectrum class of antibacterial agents that are effective against both Gram-negative and Gram-positive bacteria. However, they can be associated with adverse effects such as tendonitis and phototoxicity.

**Correct Answer:** C. Levofloxacin.