Hi Ashraf
Why are you limited to those options? Is this based on your own shortlisting or someone/a company/university advising you?
What sort of technical background do you have? Ofyour list ABAP (programming) and HANA (technical aspects) are the closest technical areas.
Demand is a fickle topic. Unless a product is reaching end of life, asking about demand is quite difficult due to numerous variables (geographical location, industry, number of skilled workers already, how wide-used the product is, etc)
Regards
Colleen