What does a chronological text structure use to signal the sequence of time?
a. causes and effects
b. reactions to events
c. words or dates
d. responses to events

To explain that how things happen in order the chronological order is used by the authors. It is also referred to as sequence or time order.

Words like next, first, later, then and finally indicate the sequence of time.

For instance, while giving the description of activities it would be written as:

My cousins and I went to Shimla in India. The first thing we did there was to search for the hotel and then unpacked our things. Later, we went to the nearby market known as "Mall Road" and during our shopping, we found many interesting things displayed in the market. Next, we tasted the street foods like momos, pakodas, and other items which were delicious. It was really a great experience. Finally, we returned to the hotel and our tour guide told us the plan for the next day.

Hence, in the above paragraph italicized words indicate the sequence of time, therefore a chronological text structure use to signal the sequence of time through words or dates.