**Core Concept**
The World Health Organization (WHO) and various national health authorities recommend a safe distance between cattle sheds and human habitations to prevent the transmission of zoonotic diseases, particularly anthrax. This distance is crucial in rural areas where cattle are commonly kept in close proximity to human settlements.

**Why the Correct Answer is Right**
The recommended distance of 25 feet is based on the risk of anthrax transmission through spores that can become airborne when cattle are slaughtered or handled. These spores can be carried by wind and contaminate nearby areas, including human habitations. A safe distance of 25 feet helps to reduce the risk of inhalation and subsequent infection. This distance also takes into account the potential for spore dispersal during veterinary procedures or accidents involving infected animals.

**Why Each Wrong Option is Incorrect**
**Option A:** A distance of 5 feet is woefully inadequate to prevent anthrax transmission, as it does not account for the potential for spore dispersal through wind or animal movement.

**Option B:** A distance of 10 feet is still insufficient to mitigate the risk of anthrax transmission, as it does not provide a sufficient buffer zone to prevent airborne spores from reaching human habitations.

**Option C:** A distance of 20 feet is closer to the recommended distance but still may not be sufficient to prevent anthrax transmission, especially in areas with strong winds or dense animal populations.

**Clinical Pearl / High-Yield Fact**
The recommended distance of 25 feet between cattle sheds and human habitations is a critical public health measure to prevent anthrax transmission. This distance should be strictly adhered to in rural areas where cattle are commonly kept, and regular veterinary inspections should be conducted to ensure compliance.

**✓ Correct Answer: D. 25 feet**