Median score of 40 students is the average of the scores of $\(20^{\text {th \& 21^{\text {st \)$ students i.e. the average of $\(70 \& 70=\frac{70+70}{2}=70\)$ (= Column A quantity)

Now, the average score of all 40 students (Shown in the table above) is $\( \frac{Total marks of all students }{ Number of students}\) =

\(\frac{40 \times 3+60 \times 4+70 \times 14+80 \times 8+90 \times 11}{40}=\frac{2970}{40}=74.25(=\)$ Column B quantity)

Hence column B has higher quantity when compared with column A, so the answer is (B).