[Solved] The focus of the Vietnamizationplan introduced by President Nixon in 1969 was A)the use of napalm to denude the forests of North Vietnam. B)a surge of U.S.troops in Vietnam preceding the final withdrawal. C)a publicity campaign to explain American involvement in Vietnam. D)the gradual replacement of U.S.troops by South Vietnamese soldiers. Dinosaurs: A diverse group of reptiles of the clade Dinosauria, known from fossil evidence to have lived during the Mesozoic Era. Phenotypes: Phenotypes are the observable characteristics or traits of an organism, resulting from the interaction of its genotype with the environment. Genotypes: The genetic makeup of an organism determining its characteristic traits. Gene Pool: The complete set of unique alleles in a population or species, representing its genetic diversity and potential for evolution.