Answer:
The correct answer is option a.
Explanation:
If the economy entered a recession, then the chances of a firm defaulting on its bond would rise. As a result, its Yield to maturity would increase.
The yield spread between a corporate bond and a Treasury bond with the same maturity is an indicator of investors’ risk aversion as well as their attitude regarding the economy and corporate profits (optimism/pessimism).
In case the economy appeared to be moving towards a recession, this spread should widen. This change in spread would be even more in case credit strength of a firm is weakened.