((a)) ** .—** In the case of an eligible child under subchapter II of this chapter whose only covered birth defect is spina bifida, a monetary allowance shall be paid under subchapter I of this chapter. In the case of an eligible child under subchapter II of this chapter who has spina bifida and one or more additional covered birth defects, a monetary allowance shall be paid under subchapter II of this chapter. In the case of a child eligible for benefits under subchapter I or II of this chapter who is also eligible for benefits under subchapter III of this chapter, a monetary allowance shall be paid under the subchapter of this chapter elected by the child.

((b)) ** .—** An individual may only be provided one program of vocational training under this chapter.