Final answer:
The word 'Belgian' should be capitalized because it is a proper adjective derived from the proper noun Belgium, which is the name of a country.
Step-by-step explanation:
The word from the sentence that should be capitalized is 'Belgian.' In English, proper nouns, including nationalities, languages, and words derived from proper nouns, should be capitalized.
'Belgian' refers to something or someone from Belgium, a country, and therefore, it is a proper adjective and should be capitalized. The correct answer is A) Belgian.