**Core Concept**
The question tests the understanding of antibiotic resistance mechanisms, specifically those involving aminoglycoside-inactivating enzymes. Aminoglycosides are a class of **antibiotics** that inhibit protein synthesis by binding to the bacterial **30S ribosomal subunit**. However, certain bacteria can produce enzymes that inactivate these antibiotics, rendering them ineffective.

**Why the Correct Answer is Right**
The correct answer is a drug that is not significantly affected by the common aminoglycoside-inactivating enzymes. These enzymes typically modify the aminoglycoside molecule, making it unable to bind to the ribosome. The most effective drug against such organisms would be one that is less susceptible to these modifying enzymes.

**Why Each Wrong Option is Incorrect**
**Option A:** This choice is incorrect because it is likely an aminoglycoside that is susceptible to inactivating enzymes.
**Option B:** Similarly, this option is probably another aminoglycoside that can be inactivated by bacterial enzymes.
**Option C:** This choice might be an antibiotic from a different class but is not the most effective against bacteria with aminoglycoside-inactivating enzymes.

**Clinical Pearl / High-Yield Fact**
It's crucial to remember that **amikacin** is often effective against bacteria that produce aminoglycoside-inactivating enzymes because it is less susceptible to these enzymes compared to other aminoglycosides like **gentamicin** and **tobramycin**.

**Correct Answer:** D. Amikacin.