If
\(
I_n = \int_0^a (a^2 - x^2)^n \, dx
\)
where \( n \) is a positive integer, then the relation between \( I_n \) and \( I_{n-1} \) is:
(A) <span class="math-tex">\(\rm I_n = \left(\dfrac{2na^2}{2n+1}\right)I_{n-1}\)</span>
(B) <span class="math-tex">\(\rm I_n = \left(\dfrac{2n^2a^2}{2n+1}\right)I_{n-1}\)</span>
(C) <span class="math-tex">\(\rm I_n = \left(\dfrac{2na^2}{2n-1}\right)I_{n-1}\)</span>
(D) <span class="math-tex">\(\rm I_n = \left(\dfrac{2n^2a^2}{2n-1}\right)I_{n-1}\)</span>