Let the annual demand be \( D \) (in number of batteries). In option 1 (making the batteries), the total cost is the sum of the fixed cost and the variable cost. Therefore, the total cost for option 1 is:
\[
{Total Cost (Option 1)} = 2,00,000 + 70D
\]
In option 2 (buying the batteries from the market), the total cost is simply the price per battery multiplied by the number of batteries. Therefore, the total cost for option 2 is:
\[
{Total Cost (Option 2)} = 90D
\]
At the break-even point, the total costs of both options are equal. Therefore, we can set the two expressions equal to each other:
\[
2,00,000 + 70D = 90D
\]
Solving for \( D \):
\[
2,00,000 = 90D - 70D
\]
\[
2,00,000 = 20D
\]
\[
D = \frac{2,00,000}{20} = 10,000
\]
Thus, the annual demand at which the company should switch from buying to making the batteries is approximately 10,000 batteries. Hence, the correct answer is between 9995 and 10005.