Select the best response from below. Assume that an investor currently holding stock in Miller Corporation wants to add the stock of either Bud Corporation or Coors Corporation to her portfolio. All three stocks have the same expected return and volatility. The correlation between Miller and Bud is -0.06; and between Miller and Coors is +0.06. Portfolio risk is expected to:
a) Decline more when the investor buys Bud
b) Decline more when the investor buys Coors
c) Increase when either Bud or Coors is bought
d) May decline or increase depending on other factors