Concept:Adding two fractions with conjugate surds in the denominator simplifies by using the identity (a+b​)(a−b​)=a2−b.Explanation:First, write the sum as a single fraction: 6+3​1​+6−3​1​.The common denominator is (6+3​)(6−3​).Multiply out: (6+3​)(6−3​)=62−(3​)2=36−3=33.Add the numerators: (6−3​)+(6+3​)=6+6=12 (the 3​ terms cancel).So the sum is 3312​.Reduce the fraction by dividing numerator and denominator by 3: 33÷312÷3​=114​.Therefore, the correct answer is 114​.Answer:C. 4/11