Portfolio Managers $($PMs$)$ have strived to increase Expected Returns above inflation and to seek new diversifiers for portfolio to compensate for the fact that the correlation between stocks and bonds have become positive in $2022.$ To this end, fund managers who have a free mandate have made several modifications to boost returns and reduce the volatility of their portfolio. Please mark the only STRATEGY that is clearly INCORRECT to achieve the stated objectives

a$.$

PMs can increase the Beta of the equities part of the portfolio and increase its exposure to credit risk to capture higher bond yields $($and spreads$)$

b$.$

PMs can increase expected returns by carefully reducing the liquidity of their portfolio. For example, they can increase their exposure to less liquid assets, such as private placements in debt and equity markets

c$.$

PMs can add Returns and manage the volatility of the Fund by addting Alternative Assets $($ALTs$),$ such as hedge funds and managed futures, because they often have low correlation with stocks and bonds

d$.$

PMs can simultaneously increase Expected Returns and reduce volatility by increasing leverage