What did Clark Clifford’s study about Vietnam conclude

Clifford took office committed to rethinking Johnson's Vietnam policies, and Vietnam policy consumed most of his time. He had argued against escalation in 1965 in private counsel with the president, but then provided public support for the president's position once the decision was made. At his confirmation hearing, he told the Armed Services Committeeof the U.S. Senate that the limited objective of the U.S. was to guarantee to the people of South Vietnam the right of self-determination.

Explanation:

b. native americans them