Let the sum of an infinite $\mathrm{G}.\mathrm{P}.$, whose first term is $a$ and the common ratio is $r$, be $5$. Let the sum of its first five terms be $\frac{98}{25}$. Then the sum of the first $21$ terms of an $\mathrm{AP}$, whose first term is $10ar, n^{\mathrm{th}}$ term is $a_n$ and the common difference is $10{\mathit{ar}}^2$, is equal to

• Correct answer
  A

  $21a_{11}$
• B

  $22a_{11}$
• C

  $15a_{16}$
• D

  $14a_{16}$

Hence, the correct answer is option: 'A'.