The correct options are
B Prevent hardening of stool.
C Increase fibre content in diet.
Diets consisting of green vegetables, fruits like banana, millets like ragi, pearl millet, foxtail millet, kodo millet etc., are rich in fibre content. Fibre deficiency in food leads to constipation which should be the possible medical condition Manu is suffering from. Sufficient fibre in daily food acts as roughage and prevents hardening of stool after digestion.