Declining production of stomach acid and intrinsic factor increase the risk for deficiency of among older adults.

Declining production of stomach acid and intrinsic factor increase the risk for deficiency of Vitamin B-12 among older adults.
also called cobalamin, is essential for functioning of the brain and nervous system. Vitamin B-12 can be found in animal sources including dairy products, eggs, fish, meat, and poultry. 

Amutation is basically the change in the gene, caused by alteration of single based units in the dna, or the genes or chromosomes were rearranged in the dna

Ithink it's c (70)