The correct responses regarding how American colonists responded to the passage of the Townshend Acts of 1768 are:
A) They formed committees of correspondence to rally opposition to British policies and educate colonists about their rights.
B) They organized boycotts of British goods, and merchants signed nonimportation agreements vowing not to buy or sell British goods.
C) This option does not apply, as the "Olive Branch Petition" was sent in 1775 as a last attempt at reconciliation, after the tensions had escalated and well after the Townshend Acts were passed.
Therefore, the correct choices are A and B.