Bonds are rated as Investment Grade $($IG$)$ or High Yield $($HY$)$ where:

Multiple Choice

HY typically comes with a better rating and less risk.

IG typically comes with a better rating and lower yield.

HY bonds spread vs risk$-$free rate $($RFR$)$ is smaller than IG spread vs risk$-$free rate.

IG bonds were rated at issuance as such, and don't change over time.