What is the difference between DRIs, RDAs, AI, and UL in nutritional recommendations?

What is the difference between DRIs, RDAs, AI, and UL in nutritional recommendations?

• A. DRIs are the umbrella set; RDAs meet the needs of nearly all healthy individuals; AI are estimates when data are insufficient; UL is the maximum intake unlikely to cause harm
• B. DRIs are only for athletes; RDAs are above all; AI is lower than RDA; UL is recommended limit for all
• C. DRIs are dietary reference assays; RDAs are random data allowances; AI are artificial intakes; UL is unknown limit
• D. DRIs are only about calories; RDAs about vitamins; AI about minerals; UL about protein

Answer: (A)