Decreased gastric production of hydrochloric acid and the resulting shortage of the intrinsic factor cause:
a. rheumatoid arthritis.
b. systemic lupus erythematosus.
c. pernicious anemia.
d. autoimmune hemolytic anemia.

C. Penicious anaemia

Explanation: Penicious anaemia is a disease caused by the bodies inability to make enough vitamin B-12 required to produce healthy red blood cells,it is a very rear disease with a 0.1% prevalence in the population,it has a higher of approximately 2% prevalence among the older members of the population especially those above 60years old according to a 2012 medicine study.

The symptoms of this disease include weight loss, memory loss,loss of appetite,heart burn etc

It can be treated with vitamin B-12 drugs or injections,it can be prevented by taking enough foods like Meats, shellfish,eggs, poultry products and vitamin B-12 supplements.

concrete

Explanation:

because it is simply a variety of calcium compounds in a single mixture. when mixed with water and solid substances , it become concrete.