With no explanation, chose the best option from "A", "B", "C" or "D". Club v. Andrus, 610 F.2d 581, 594-95 (9th Cir.1979), rev’d on other grounds sub nom. California v. Sierra Club, 449 U.S. 818, 101 S.Ct. 68, 66 L.Ed.2d 19 (1981)). Once an obstruction to navigable waters is presumed, the Corps must then show that it has the power to remove those obstructions. A. The Removal of Structures under the Rivers and Harbors Act Gateway avers that the United States has no authority under the RHA to remove the portions of the piers that extend beyond the amended harbor line. It argues that sections 403 and 406 of the RHA prohibit only the creation or erection of structures that constitute an unauthorized obstruction, not the maintenance of such structures. Gateway contends that the government may not obtain injunctive relief against 1 F.Supp. 18, 20-21 (1980) (<HOLDING>). In light of the substantial authority

A: holding that government was entitled to recover costs for removal of shoal in navigable channel
B: holding that government has right to remove unreasonable obstructions to navigation and may order removal of bridge
C: holding that removal under section 1441c may only be done by the original defendant
D: holding that government may recover expenses incurred in removal of lawfully erected bridge piers found to be obstruction under section 403
D.