Jeremy founded a company. He issues 100,000 shares of series A stock for his own $100,000 investment. He then goes through three further rounds of investment, as shown below: Round Price Number of Shares Series B $1.00 500,000 Series C $1.50 300,000 Series D $1.75 500,000 What is the post-money valuation for the series D funding round?

a. $2.45 million

b. $1.23 million

c. $1.72 million

d. $2.21 million