Given this code, which statement about the database table "documents" could be expected to be true?
class Document < ActiveRecord::Base
belongs_to :documentable, polymorphic: true
end
class Product < ActiveRecord::Base
has_many :documents, as: :documentable
end
class Service < ActiveRecord::Base
has_many :documents, as: :documentable
end
a. It would include a column for :type.
b. It would include columns for :documentable_id and :documentable_type.
c. It would include columns for :documentable and :type.
d. It would include a column for :polymorphic_type.
