With reference to the provisions made under the National Food Security Act, $2013$ consider the following statements:

I. The families coming under the category of 'below poverty line (BPL)' only are eligible to receive subsidised grains.

II. The eldest woman in a household, of age $18$ years or above, shall be the head of the household for the purpose of issuance of a ration card.

III. Pregnant women and lactating mothers are entitled to a take-home ration' of $1600$ calories per day during pregnancy and for six months thereafter.

Which of the statements given above is/are correct?