A benchmark market value index is comprised of 3 stocks. Yesterday the three stocks were priced at $10, $18, and $40. The number of outstanding shares for each is 610,000 shares, 510,000 shares, and 210,000 shares, respectively. If stock prices changed to $14, $16, and $42 today respectively, find out the 1-day rate of return on the index?
A 6.00%
B 12.62%
C 7.77%
D 9.29%