Suppose there is a simple index of three stocks, stock ABC, stock XYZ, and
stock QRS. Stock ABC opens on day 1 with 5000 shares at $3.25 per share.
Stock XYZ opens on day 1 with 500 shares at $8.25 per share. Stock QRS
opens on day 1 with 10,000 shares at $4.75 per share. The price of stock ABC
on day 8 begins at $2.80. The price of stock XYZ on day 8 begins at $7.50.
Stock QRS opens on day 8 with a price of $4.10 per share. Assume that each
stock has the same number of shares that it opened with on day 1. What is
the rate of change of this simple index over 1 week?
A. -15.5%

B. -13.4%

c. 15.5%

D. 13.4%