The most common type of mortgage-backed security is OA the securitized mortgage, a security which increases the liquidity of otherwise illiquid mortgages. O B. the participation certificate, a security which passes the borrower's mortgage payments equally among all the owners of the certificates. OC collateralized mortgage obligations, a security which reduces prepayment risk. D. the mortgage pass-through, a security that has the borrower's mortgage payments pass through the trustee before being disbursed to the investors