(a) It is necessary to accomplish the mission of the agency effectively and economically, and

(b) You are directed to perform a long-term assignment at another official station; or

(c) Your agency otherwise could authorize temporary duty travel and pay travel allowances, including payment of subsistence expenses, under chapter 301 of this title for the long-term assignment; or

(d) Your agency determines it would be more advantageous, cost and other factors considered, to authorize a long-term assignment; and

(e) You meet any additional conditions your agency has established.