Correct option is D
If 351 means 'students like maths'; 197 means 'we are students' and 748 means 'they are parents
351=” Students like maths “
· 197 =”we are students “
· 748 =”they are parents”
· From this student (common in the first and second sentence) = 1 (common in the same)
· Are (common in second and third sentence) =7 (common in the same)
· So, the remaining word in the second sentence is We and their code will be as 9