**Core Concept**
In microbiology, resistance forms refer to mechanisms by which bacteria evade the effects of antibiotics. Primary resistance forms are inherent or innate resistance mechanisms that bacteria possess before exposure to antibiotics. These mechanisms are crucial for the bacteria's survival in the absence of antibiotics.

**Why the Correct Answer is Right**
Primary resistance forms include intrinsic resistance, which is an inherent property of a bacterial species, and natural resistance, which is an inherent property of a specific strain within a species. Intrinsic resistance is often due to the presence of innate efflux pumps or altered target sites for antibiotics. In contrast, acquired resistance forms are developed through genetic mutations or horizontal gene transfer after exposure to antibiotics.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because intrinsic resistance is indeed a primary resistance form.
**Option B:** This option is incorrect because natural resistance is also a primary resistance form.
**Option C:** This option is incorrect because secondary resistance forms are developed through genetic mutations or horizontal gene transfer after exposure to antibiotics.

**Clinical Pearl / High-Yield Fact**
It's essential to differentiate between primary and secondary resistance forms when designing antibiotic treatment strategies. Primary resistance forms are often inherent to a bacterial species or strain and cannot be altered, whereas secondary resistance forms can be developed or acquired through exposure to antibiotics.

**Correct Answer: D. Secondary resistance forms are not primary resistance forms.**