Deficiency of vitamin $C$ causes

Which of the following is a protein-deficiency disease?

Among the five statements $(a - e)$ given below,identify the three correct statements regarding Beriberi:
$(a)$ This debilitating disease is found in the sub-Saharan population of Africa.
$(b)$ It is a deficiency disease caused by the lack of Thiamine (Vitamin-$B_1$).
$(c)$ It is a nutritional deficiency in older children and infants caused by a chronic lack of dietary protein.
$(d)$ This deficiency is commonly found in countries where polished rice is the staple food.
$(e)$ Symptoms include nerve weakness,pain,paralysis,muscle wasting,loss of appetite,mental confusion,and eventually heart failure.

The function of vitamin $D$ is

Which one of the following pairs is not correctly matched?

Which group of three of the following five statements $(I-V)$ is correct regarding beriberi?
$I.$ $A$ crippling disease prevalent among the native population of sub-Sahara Africa.
$II.$ $A$ deficiency disease caused by lack of thiamine (vitamin-$B_{1}$).
$III.$ $A$ nutritional disorder in infants and young children when the diet is persistently deficient in essential protein.
$IV.$ Occurs in those countries where the staple diet is polished rice.
$V.$ The symptoms are pain from neuritis,paralysis,muscle wasting,progressive oedema,mental deterioration and finally heart failure.