Firm A and Firm B are perfectly negatively correlated. If your portfolio contains an equal dollar amount of stock in Firm A and B$,$ what will be the risk of the portfolio?

It will be riskless

Firm B$\text{'}$s stock will influence it more because its variance is greater

Firm A will influence it more because its variance is greater

Firm A$\text{'}$s stock will influence it more because its standard deviation is greater