**Core Concept**
The transmission rate of HIV by needlestick injury in health professionals is a critical concern due to the risk of occupational exposure. This phenomenon is influenced by the viral load of the infected individual, the type of needle used, and the location of the injury.

**Why the Correct Answer is Right**
The risk of HIV transmission following a needlestick injury is estimated to be around 0.3% (1 in 300) for percutaneous exposure to HIV-infected blood. This low transmission rate is attributed to the presence of the HIV virus in a relatively small amount of blood, which may not be sufficient to infect the recipient. Additionally, the skin's natural barrier function helps to prevent the entry of the virus. The type of needle used, whether hollow or solid, does not significantly affect the transmission rate.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it overestimates the risk of HIV transmission following a needlestick injury. The actual risk is significantly lower.
**Option B:** This option is incorrect as it suggests a higher transmission rate than what is actually observed. The low viral load in most cases contributes to the low transmission rate.
**Option C:** This option is incorrect as it implies a higher risk of transmission following a needlestick injury. While the risk is present, it is not as high as this option suggests.

**Clinical Pearl / High-Yield Fact**
Healthcare workers exposed to HIV through needlestick injuries should undergo post-exposure prophylaxis (PEP) immediately, which involves antiretroviral therapy to prevent infection.

**Correct Answer:** B. 0.3%