Answer:
Besides
Step-by-step explanation:
A word or phrase whose function is to provide a transition between two or more sentences, paragraphs or ideas in order to help make ideas flow smoothly are called "Transitions words". Depending on the transition word used, they may show similarity, illustrate a point, give examples, express contrast between one idea and another, add information to a previous point, among others.
The word "besides" is a transition word because it provides a transition between the second and third sentences by adding more information to the second sentence. Other transition words with the same function are moreover and furthermore.