An increase in growth rate of potential GDP (keeping actual growth rate unchanged) would most likely allow the government to pursue expansionary monetary/fiscal policies. An increase in growth rate of potential GDP reduces expected credit risk for all fixed income securities and hence narrows the credit spreads.
Note: The question does not provide any information about actual growth rate, hence we have to assume it to be constant for a least likely type question.
(Study Session 4, LOS 15.c)
