**Core Concept**
Aminoglycosides are a class of antibiotics that inhibit protein synthesis by binding to the bacterial 30S ribosomal subunit. In topical formulations, aminoglycosides are often combined with other antibiotics to enhance their efficacy and reduce the risk of resistance.

**Why the Correct Answer is Right**
The correct answer is **Neomycin**. Neomycin is an aminoglycoside antibiotic that is commonly used in topical formulations, including creams and ointments, to treat infections such as minor cuts, scrapes, and burns. When combined with polymyxin and bacitracin, neomycin provides a broad-spectrum antimicrobial effect, making it effective against a wide range of bacteria. The combination of these three antibiotics is often used to treat topical infections, such as those caused by Pseudomonas aeruginosa.

**Why Each Wrong Option is Incorrect**
**Option A:** **Gentamicin** is an aminoglycoside antibiotic, but it is not typically used in topical formulations for the treatment of minor infections.
**Option B:** **Tobramycin** is another aminoglycoside antibiotic, but it is not commonly combined with polymyxin and bacitracin for topical use.
**Option C:** **Amikacin** is an aminoglycoside antibiotic, but it is not typically used in topical formulations and is not commonly combined with polymyxin and bacitracin.

**Clinical Pearl / High-Yield Fact**
When using topical antibiotics, it's essential to note that aminoglycosides, including neomycin, can cause renal toxicity and ototoxicity. Therefore, they should be used with caution and for the shortest duration necessary to treat the infection.

**Correct Answer:** B. Neomycin