Section 51.405 - Burden of proof(a) Upon receipt of a bona fide request for interconnection, services, or access to unbundled network elements, a rural telephone company must prove to the state commission that the rural telephone company should be entitled, pursuant to section 251(f)(1) of the Act, to continued exemption from the requirements of section 251(c) of the Act.(b) A LEC with fewer than two percent of the nation's subscriber lines installed in the aggregate nationwide must prove to the state commission, pursuant to section 251(f)(2) of the Act, that it is entitled to a suspension or modification of the application of a requirement or requirements of section 251(b) or 251(c) of the Act.(c) In order to justify continued exemption under section 251(f)(1) of the Act once a bona fide request has been made, an incumbent LEC must offer evidence that the application of the requirements of section 251(c) of the Act would be likely to cause undue economic burden beyond the economic burden that is typically associated with efficient competitive entry.(d) In order to justify a suspension or modification under section 251(f)(2) of the Act, a LEC must offer evidence that the application of section 251(b) or section 251(c) of the Act would be likely to cause undue economic burden beyond the economic burden that is typically associated with efficient competitive entry.