Answer: d. A B and C are correct.
Explanation:
A bond's price and it's Yield to Maturity (YTM) are inversely related such that when Yield to Maturity rises, the price of the bond falls. This is a because a higher YTM signifies that the bond is riskier so it will compensate by being cheaper.
If a bond is downgraded by Ratings agencies then it means that the bond is now riskier. As it is riskier investors will charge more interest for taking on the risk. The interest is the YTM and so it rises.
A Subordinate bond means that if the company were to go into bankruptcy for instance, the Subordinate bond would only be paid for after the bond that is not Subordinated. This means that there is a chance that Subordinate bond holders will not get anything from the liquidation of the company. Investors will therefore charge a higher YTM to cater for the risk that this happens.