Question

The change required for the sentence underlined at [3] is _______.

• A. NO CHANGE
• B. al-Khwarizmi, who worked in the 9th century CE developed
• C. al-Khwarizmi who worked in the 9th century CE, developed
• D. al-Khwarizmi, who worked in the 9th century CE, developed

Answer 1

Answer: (D)

al-Khwarizmi, who worked in the 9th century CE, developed

The clause "who worked in the 9th century CE" is a non-restrictive relative clause as it is not essential to the meaning of the sentence. This is why it requires the commas- "The Persian mathematician al-Khwarizmi, who worked in the 9th century CE, developed...". So, the correct answer is option D.