Final answer:
Option c is correct: a "fallen angel" is a bond that fell from an A rating or above to a BBB rating.
Step-by-step explanation:
The correct statement concerning bond ratings is option c. A "fallen angel" is a bond that fell from an A rating or above to a BBB rating. Moody's is not the sole provider of bond ratings, as there are other rating agencies such as Standard & Poor's and Fitch Ratings. Investment grade bonds include those bonds that have a rating of BBB or higher, not just A or higher. Bond ratings consider factors such as the creditworthiness and risk associated with a bond, including the potential price volatility.