Final answer:
The combined sentence using relative pronoun would be 'My grandmother, who never took a singing lesson, is one of the best singers I know.' Relative pronouns link sentences smoothly and make them complex. Its use improves writing skills. Option A is correct
Step-by-step explanation:
The correct sentence combination using a relative pronoun would be option A: 'My grandmother, who never took a singing lesson, is one of the best singers I know.' Relative pronouns such as 'who' connect two sentences by replacing the subject in the second sentence, creating a more complex but smoother single sentence. Here, the relative pronoun 'who' is connecting the sentence about your grandmother not taking a singing lesson with the sentence about her being one of the best singers.
Other options like B, C, and D use coordinating conjunctions or semi-colon for combining sentences which is different from using relative pronouns.
Understanding of relative pronouns can greatly increase your writing ability by allowing you to create more complex and informative sentences. Always remember, the relative pronoun must agree with its antecedent and helps adding additional information about the subject or the antecedent without starting a new sentence.
Learn more about Relative Pronouns