Final answer:
The correct verb is 'conozco' because it expresses familiarity with someone or something.
Step-by-step explanation:
The correct verb in this sentence is b) conozco
This is because the verb conocer is used when talking about knowing or being familiar with people, places, or things. In this context, the sentence is saying 'I know the works of the famous artists Velázquez and Goya.'
Here, the speaker is expressing their familiarity with the artworks of these famous artists.
Learn more about conjugation of the verb 'conocer'