Final answer:
The transition word indicating the start of a sequence is 'Initially.' Transition words like 'first,' 'second,' and 'finally' guide readers through a sequence of ideas or events in writing.
Step-by-step explanation:
The transition word that indicates the beginning of a sequence of events in a paragraph is d) Initially. When writing a paragraph, using transition words effectively can create a clear and logical flow of ideas. For example, consider the following sequence: First, I researched the topic; second, I wrote a rough draft; and finally, I reviewed and edited my work to create the final draft. Transition words such as first, second, and finally serve as signals to readers, outlining the order of actions or thoughts and aiding in the smooth progression of the narrative or argument.