Tammy founded her business using $200,000 of her own funds, issuing herself 200,000 shares of stock. An angel investor bought an additional 100,000 shares for $150,000. She now sells another 500,000 shares of stock to a venture capitalist for $1.5 million. What is the post-money valuation of the company? a) $1,200,000 b) $1,320,000 c) $2,400,000 d) $3,600,000