I . . . . . always capital.

Answer: Option A

Remember that verbs change their form depending on the subject of the sentence.
The subject of the sentence is "I", which is a singular first-person pronoun.
Option A ("am") is the correct form of the "to be" verb when used with "I".
Option B ("is") is used with singular third-person pronouns like "he," "she," and "it".
Option C ("has") is the third-person singular form of the verb "to have".
Option D ("do") is a helping verb and doesn't fit the sentence structure.
Therefore, the complete sentence is: "I am always capital."