Which method call returns true only if the currently logged in user has the catalog_admin role and in no other case?

Which method call returns true only if the currently logged in user has the catalog_admin role and in no other case?
A . g_user.hasRole(‘catalog_admin’)
B . g_user.hasRoleExactly(‘catalog_admin’)
C . g_user.hasRoleOnly(‘catalog_admin’)
D . g_user.hasRoleFromList(‘catalog_admin’)

Answer: B