Your client has guidelines for you to only buy investment$-$grade long duration corporate bonds when spreads are $2\%$ spread to $10-$year Treasury bonds. $10-$year Treasury rates are $4\%.$ What required yield are you looking for the long duration corporate bond to have based on these guidelines? You find a corporate rate at $7\%$ for a BB$-$rated bond. Do you buy the bond for him? Why or why not?