The idea of controlling humans through biological engineering is an example of what?

Read these lines from denise levertov's poem "in thai binh (peace) province": it is that life, unhurried, sure, persistent, i must bring home when i try to bring the war home. child, river, light. here the future, fabled bird that has migrated way from america, nests, and breeds, and sings, common as any sparrow. which statement best interprets the author's use of metaphor in these lines? a. the metaphor of home suggests that american foreign policy should turn inward. b. the metaphor of the river suggests that life moves ear forward. c. the metaphor of the fabled bird suggests that the war has left americans divided. d. the metaphor of the fabled bird suggests that vietnam will rise to fight again.