Hello,

All the options you have mentioned has a high scope. In the real world, during a treatment process , all the three science is important and has to be cared. any mistake in one section will lead to loss of a life.

You have to choose as per what you want to do and how you want to make your career. if you are confused then search for individual branch and learn what it is and what it actually deals with. Which is the branch in which you can do your best.

On the part of salary, it will increase with respect to your experience and performance. Salary also varies with work place also. Highly recognized organizations have high salary but selection process is tough.  There is no field which has no scope. people are working to make money even from the waste.

Hope it helps!