一个正方体的棱长总和是48cm，它的表面积是 （    ） cm²，体积是（    ） cm³。 

Which of the following statements is TRUE（）

A. When a rating agency downgrades a security, the bond’s price usually falls.

B. Technical default usually refers to the issuer’s failure to make interest or principal payments as scheduled in the indenture.

C. Default risk is important because if a bond issuer defaults, the bondholder likely loses his entire investment.