Which of the following does Python allow to be the first character in a variable name? Select all that apply

Lower case letters $($a$,$ b$,$ c$,...)$

Upper case letters $($A$,$ B$,$ C$,...)$

Digits $(1,2,3,..)$

Symbols $(!,$ @$,$$$,..)$

Underscores $(\_)$

Apostrophes and quotation marks $(\text{'},")$