Fixed Income - Investment and non investment grade securities

If the bond has high quality, it should generally be investment grade bond, in which case, investors focus on spread risk which includes market liquidity risk and credit migration risk.

Default risk is focus of the investors when the bond is of non-investment grade or junk bond. So as per my opinion, the answer to this question should be option C. However, the answer as per CFA institute is A. Please explain why?