Assume you sell short $100$ shares of common stock at $ $30$ per share, with initial margin at $50\%.$ What would be your rate of return if you repurchase the stock at $$35$ per share? a$)-33\mathrm{.}33\%$ b$)-25\mathrm{.}63\%$ c$)-57\mathrm{.}14$ d$)-77\mathrm{.}23$