The word which can be best used to complete the given sentence is "must"
What is Diction?
This refers to the word choice which a writer chooses to use when writing to convey his feelings and intentions.
With this in mind, we can see that the given sentence is talking about the need to find a new mascot and this was of great importance so we can see that this is obligatory so the word "must" should be used.
Read more about diction here:
https://brainly.com/question/1503891
