The sentence has been changed from the passive voice to the active voice as follows:
The active voice is used when the subject performs the action in the text. The verb is "embarrassed" and it was Grandpa who caused this response from Martin.
So, since Grandpa is the subject, he should be described as the person who performs the action. This is the objective of the active voice. But in the passive voice, the subject receives the action.
Learn more about the active and passive voice here:
https://brainly.com/question/25897080
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