; (ii) if the President determines that the person or other entity to which the sanctions would otherwise be applied is a sole source supplier of the defense articles or defense services, that the defense articles or defense services are essential, and that alternative sources are not readily or reasonably available; or (iii) if the President determines that such articles or services are essential to the national security under defense coproduction agreements; (B) to products or services provided under contracts entered into before the date on which the President publishes his intention to impose sanctions; (C) to— (i) spare parts; (ii) component parts, but not finished products, essential to United States products or production; or (iii) routine servicing and maintenance of products, to the extent that alternative sources are not readily or reasonably available; (D) to information and technology essential to United States products or production