Consider the single factor APT. Portfolio A has a beta of $1\mathrm{.}3$ and an expectod return of $21\%.$ Portfolio B has a beta of $0\mathrm{.}7$ and an expected return of $17\%.$ Portfolio C has a beta of $1\mathrm{.}5$ and an expected return of $22\%.$ The risk$-$free rate of return is $88\%.$ If you wanted to take advantage of an arbitrage opportunity, you should take a short position in portfolio and a long position in portfolio $q,.$