Which of the following regular expressions will match a phone area code with or without parentheses?

That is$,$ it must match a $3$ digit number where the first digit is a numeral $2$ or greater. For example, it must

match $345$ or $(345)$ but not $145$ or $(145).$ Hint $$ there is more than one correct response.

a$.[2-9]\backslash$d$\{2\}|([2-9]\backslash$d$\{2\})$

b$.[2-9][0-9]\{2\}|(\backslash ([2-9][0-9]\{2\}\backslash ))$

c$.([2-9]\backslash$d$\{2\})|(\backslash ([2-9]\backslash$d$\{2\}\backslash ))$

d$.([2-9]\backslash$d$\{2\})|([2-9]\backslash$d$\{2\})$

e$.([2-9][0-9]\{2\})|(\backslash ([2-9][0-9]\{2\}\backslash ))$

f$.$ None of the above