Concept:
Healthcare waste consists of both hazardous and non-hazardous waste.
According to biomedical waste management guidelines:
• About 75--90% of healthcare waste is general non-risk waste.
• Only a smaller proportion is infectious or hazardous.
Most of the non-risk waste originates from:
• Administrative activities
• Housekeeping services
• Packaging materials
• Food waste
Such waste is comparable to ordinary domestic waste.
Step 1: Analyze Assertion (A).
The statement that 75--90% of healthcare waste is non-risk or general waste is scientifically correct.
Hence, Assertion (A) is correct.
Step 2: Analyze Reason (R).
Administrative and housekeeping sections of healthcare facilities generate large quantities of ordinary non-hazardous waste.
Hence, Reason (R) is also correct.
Step 3: Check whether Reason explains Assertion.
The reason correctly explains why a major portion of healthcare waste is categorized as general non-risk waste because it originates mainly from non-clinical activities.
Therefore, Reason (R) is the correct explanation of Assertion (A).
Hence, the correct answer is:
\[
\boxed{(A)\ \text{Both (A) and (R) are correct and (R) is the correct explanation of (A)}}
\]