Why might it sometimes be difficult for a president to rely on the advice of cabinet members?

As a matter of fact, when presidents need advice on policy making, they are more likely to rely on the White House staff than on cabinet members. Sometimes, presidents have difficulty to rely on cabinet members since these members cannot contribute as much to deliberations in policy areas as they have shown to have limited areas of expertise and to not know enough about it.

b) the planets year length would be longer

hope this !