; and (B) is not required to undertake new scientific or technical research unless the new scientific or technical research is essential to a reasoned choice among alternatives, and the overall costs and time frame of obtaining it are not unreasonable. 107. Timely and unified federal reviews (a) Lead agency (1) Designation (A) In general If there are two or more participating Federal agencies, such agencies shall determine, by letter or memorandum, which agency shall be the lead agency based on consideration of the— (i) magnitude of agency’s involvement; (ii) project approval or disapproval authority; (iii) expertise concerning the action’s environmental effects; (iv) duration of agency’s involvement; and (v) sequence of agency’s involvement. (B) Joint lead agencies In making a determination under subparagraph (A), the participating Federal agencies may appoint such State, Tribal, or local agencies as joint lead agencies as the involved Federal agencies shall determine appropriate. Joint lead agencies shall jointly fulfill the role described in paragraph (2). (2) Role A lead agency shall, with respect to a proposed agency action— (A) supervise the preparation of an environmental document if, with respect to such proposed agency action, there is more than one participating Federal agency; (B) request the participation of each cooperating agency at the earliest practicable time; (C) in preparing an environmental document, give consideration to any analysis or proposal created by a cooperating agency; (D) develop a schedule, in consultation with each cooperating agency, the applicant, and such other entities as the lead agency determines appropriate, for completion of any environmental review, permit, or authorization required to carry out the proposed agency action