In which area does congress most often defer to the executive?

Congress is likely to defer to the congress on issues to do with foreign policy.

It is widely accepted that the president is able to pursue foreign policy in a better way than congress.This is because during wars congress is often able to defer to the president, and voting behaviors often swift towards the president ideological orientation. Presidents are also able to pursue their foreign policy agenda especially during wars.

Sorry to say i don't have the answer