Answer:
c. Because.
Step-by-step explanation:
Transitional words are those words that joins two or more ideas in a sentence. They act as a connecting agent in linking words and ideas that ca, at the same time, act as full sentences on their own.
There can be many uses of these transitional words, either to give alternatives, to compare or to provide evidence to the supporting words. In the case of the provided sentence,
I take my time getting to the park on May Day because the track meet is the last thing on the program
the transitional word is "because" for it provides the evidence to support the cause, i.e. the track meet. Also, it joined the two ideas of the sentence, making it a transitional word.