Java

Which of the following are valid java identifiers?

String upswork

b$.$ Strine$\_$upWbrk:

c$.$ String up$.$work

d$.$ String true:

e$.$ String Public:

f$.$ String $1980\_$s;

Ack ONE option

a$,$ b$,$ c$,$ d

b$,$ e$,$ I

$a,b,e,f$

Clear selecition