Both the nouns; J W Mariott and Baker Street are proper nouns. Generally, we don't use articles before proper nouns, hence option B is correct. We don't use the article 'a' when the noun is specific, plus it's a proper noun, so the first option is incorrect. Options C and D both have 'the' in their set of answers, we can't use 'the' since the noun is a proper noun, hence these two options are wrong.