A positive integer with \(n\) number of digits is called **special** (\(\overline{a_1a_2a_3a_4\dots a_{n}}\)), if
\[\overline{a_1a_2a_3a_4\dots a_{n}}+\overline{a_{n}a_{n-1}a_{n-2}\dots a_3a_2a_1}\]
has only odd digits. (\(a_{n}\neq0\).)

Which of the following could be the number of a special number's digits?

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