**Core Concept:**
Isoniazid is an anti-tuberculosis drug primarily targeting the bacteria Mycobacterium tuberculosis. It is an inhibitor of Inosine Monophosphate Dehydrogenase (IMPDH), an enzyme involved in guanine nucleotides synthesis. Cross-resistance refers to the ability of a drug to reduce the effectiveness of another drug due to shared mechanisms of resistance.

**Why the Correct Answer is Right:**
Isoniazid (INH) has several mechanisms of action against M. tuberculosis, including inhibition of IMPDH, and inducing the expression of other anti-microbial proteins. However, it is not a primary bacteriostatic or bactericidal agent like some of the other anti-tubercular drugs.

**Why Each Wrong Option is Incorrect:**
A. Ethambutol (EMB) is a primary anti-tuberculosis drug with its own unique mechanisms of action, such as inhibiting mycolic acid synthesis and interfering with the function of the cell wall of M. tuberculosis. It does not share the same mechanisms as isoniazid, making it an incorrect choice.

B. Rifampin (RIF) is another primary anti-tuberculosis drug that targets DNA-dependent RNA polymerase, inhibiting the transcription of bacterial RNA. Its mechanisms of action are distinct from isoniazid, so this option is incorrect as well.

C. Pyrazinamide (PZA) is another primary drug that acts on M. tuberculosis by inhibiting pyrazinoate mono-oxygenase, a key enzyme in the pathway of pyrazinamid biosynthesis. Similar to EMB and RIF, PZA has its own specific mechanisms of action and does not share cross-resistance with isoniazid.

D. Streptomycin (STR) is a primary anti-tuberculosis drug that interferes with protein synthesis in bacteria by binding to 16S rRNA, inhibiting the 60S ribosomal subunit. Unlike isoniazid, streptomycin has distinct mechanisms of action, making this option incorrect as well.

**Clinical Pearl:**
The concept of cross-resistance between anti-tuberculosis drugs is crucial in clinical practice. Understanding these differences will help in tailoring treatment regimens for tuberculosis patients, ensuring effective drug combinations and minimizing the development of drug-resistant strains.