Bond A has yield adv but bond B has longer duration.
If question just asks for the breakeven spread widening or from perspective of Bond B, use Bond B’s duration. If asked from Bond A perspective use Bond A’s duration. Do I have that right? This one always trips me up.
no. ALWAYS use the duration of the higher bond. Also make sure you are using the proper spread time period, the CFAI books always use quarterly spread advantage so just keep an eye for that if they give you annual yields, they may ask you to solve for quarterly.