Final answer:
Among the given options, the American Indian subtraction requires adding a schedule to the Oregon return to provide additional information about the income being subtracted.
Step-by-step explanation:
The item that requires additional information (a schedule) to be attached to the Oregon return among the options provided is the American Indian subtraction. For the Political contribution credit, no schedule is necessary as this credit can be claimed directly on the tax form with proof of a political contribution made.
Similarly, the Credit for loss of use of limbs and the Exemption for handicapped child also do not require a separate schedule; these credits should be supported by appropriate documentation or certification rather than an additional tax schedule. The American Indian subtraction, however, may require further documentation about the income to be subtracted, which means it might need a specific form or schedule attached to properly claim the subtraction on the Oregon tax return.