Marigold reported the following results from the sale of $5000$ units in May: sales $$400000,$ variable costs $$220000,$ fixed costs $$90000,$ and net income $$90000.$ Assume that Marigold increases its selling price by $5\%$ on June $1.$ How many units will have to be sold in June to maintain the same level of net income?

$4500.$

$4725.$

$4750.$

$5000.$