The correct option is
A _ / the / the
The articles 'the', 'an' and 'a' are mainly divided into definite and
indefinite. 'The' is a definite article used when the noun is specific
(or when the noun is made known to the speaker), whereas 'a' and 'an'
are used when the noun is non specific.
We do not use articles in front of proper nouns. Since 'Japanese' is a proper noun (in the first case it refers to the language, the second time it refers to the people) we omit the article in the first blank.
When the proper noun refers to a group of people, like 'the Japanese' collectively refers to the citizens of Japan, we use the definite article 'the'.
Hence options B, C and D are wrong.
The noun 'way' is specific as it expresses a particular manner in which the Japanese speak.
Hence we use the definite article 'the' for 'way'.
As explained above, the right combination is present only in option A: _/the/the, which is the correct option.