Increase in gastro-intestinal secretion and movement after ingestion of food is mainly brought about by

Vitamin $A$ is synthesized from carotene in the ...... .

Identify the incorrect statement.

$A$ patient suffering from cholera is given a saline drip because:

Choose the correct answer among the following:
$(a)$ Gastric juice contains
$(i)$ pepsin,lipase and rennin
$(ii)$ trypsin,lipase and rennin
$(iii)$ trypsin,pepsin and lipase
$(iv)$ trypsin,pepsin and renin
$(b)$ Succus entericus is the name given to
$(i)$ a junction between ileum and large intestine
$(ii)$ intestinal juice
$(iii)$ swelling in the gut
$(iv)$ appendix

$A$ person had roti and dal for his lunch. Trace the changes in those during its passage through the alimentary canal. What are the various enzymatic types of glandular secretions in our gut helping digestion of food? What is the nature of end products obtained after complete digestion of food?