Concept:
Medical hygiene practices are measures used to prevent infection and maintain health in medical and healthcare settings. These practices reduce the spread of communicable diseases and ensure patient safety.
Common medical hygiene practices include:
• Isolation or quarantine
• Sterilization of instruments
• Use of protective clothing
Step 1: Identify standard medical hygiene practices.
Among the given options, the following are recognized medical hygiene measures:
\[
\text{Isolation or quarantine}
\]
\[
\text{Sterilization of instruments}
\]
\[
\text{Use of protective clothing}
\]
Step 2: Eliminate unrelated or indirect options.
Policies and general regulations may support hygiene practices, but they are not direct hygiene procedures themselves.
Step 3: Choose the correct combination.
Thus, the correct set is:
\[
A, C, D
\]
Hence, the correct answer is:
\[
\boxed{(B)\ A, C, D\ \text{only}}
\]