The correct answer is D. Sara suddenly became very ill; therefore, she went to see her doctor
Explanation:
The semicolon (;) as the comma (;) or the period (.) is a punctuation mark that introduces a significant pause and establishes a relationship between different elements in a sentence or two different sentences. Semicolons introduce pauses that are longer than commas, but that show two ideas are connected, the use of semicolon include using semicolon to connect two independent clauses (complete and independent ideas) that are related; using semicolons if two independent clauses are linked by conjunctive adverbs such as however, consequently or therefore and using semicolon to separate elements in a list especially if these elements are long or include other punctuation marks. Considering this, the sentence "Sara suddenly became very ill; therefore, she went to see her doctor" uses semicolon correctly because there are two independent clauses (Sara suddenly became very ill / she went to see her doctor) linked by the conjunctive adverb "therefore" that implies the two clauses need to be separated by a semicolon according to grammar which is the way semicolon was used in this sentence.
