Answer:
vehemently
Step-by-step explanation:
In this exercise, you're required to use the most appropriate word among the group of answer choices provided. Also, the word that's chosen should make the sentence logical and express a complete thought.
Critically analyzing all of the words provided, the most appropriate word to complete the sentence is vehemently because we were told that the monster shouted.
Vehemently is an adverb and it means to say or do something in an intense, forceful, strong and emotional, passionate, or zealous manner.
Hence, the complete sentence would be written as follows;
"Someone stole my treasure, and someone is going to pay!" shouted the monster vehemently.