The function of the word "open" in the given sentence is it is an action word (verb)
What is a Verb?
This is the part of speech that shows the action that occurs in a sentence or also a doing word.
Hence, we can see that from the given sentences, there are two verbs here, "saw" and "open" which show the action of a person that opened a safe to view the contents.
Read more about action verbs here:
https://brainly.com/question/14584990
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