Which event most directly contributed to the end of u. s. involvement in vietnam?

a.) the u. s. military conducted a raid and massacre in the village of my lai.
b.) u. s. public opinion against the war became very high during an election year.
c.) nixon transferred control of most of the fighting to a strong south vietnamese army.
d.)violent protests erupted against the war and took place at the democratic national convention.

both are true, the congress does have the power to create banks, even if this power is not specifically described in the constitution, since there is nothing restricting it and there is power given to the congress to make "all laws which shall be necessary and proper". maryland was not allowed to tax a branch of the national bank operating there, and the supreme court decided that no state could. both of these topics were discussed in a decision of the mcculloch v. maryland case in 1819.