Final answer:
The best way to combine (1) and (2) is by stating that the colonists refused to buy stamps, and they were determined to get the Stamp Act repealed.
Step-by-step explanation:
The best way to combine (1) and (2) is option 1: The colonists refused to buy stamps, and they were determined to get the Stamp Act repealed. This option maintains clarity and coherence by explicitly connecting the two ideas with a conjunction and providing the necessary subject ('they') in the second clause. Option 2 lacks the subject ('they') in the second clause, which can cause confusion.