$1.$ An investment of $$210$ produces a perpetual stream of cash inflows. Next year, the cash inflow will be $$10\mathrm{.}50,$ and the cash inflow will grow at $5\%$ per year. What is the internal rate of return on this investment?

$2.5\mathrm{.}0\%$

$10\mathrm{.}0\%$

$12\mathrm{.}0\%$

$0\mathrm{.}0\%$