Wt is the best carrier
Well, it depends what your interests are, if you love gardening, you don't want to be working in a factory, and if you love animals, you may not want to be an engineer.
So, do a bit of research on the internet... there are thousands of possibilities!
career (lawyer, doctor, dentist, architect) or carrier (delta, united, continental, northwest)? lol! make it clear honey.. xp
Charge carriers? In which case electrons as they have a higher mobility than holes.
What do you mean 'carrier'!?