Answer:
Correct answer is It prohibited colonists from testifying in trials in London.
Step-by-step explanation:
This law known as Murder Act was allowing British officers to get away with murder because the trials were held in Britain. That is why this is a correct answer. Colonist were not able to come to London to testify, so without their testimony it was impossible to accuse soldiers for murder. That is why all other options are false. They had trial, but as we said it was practically impossible to convict them.