Question

Does someone know this?

Answer 1

Answer: the time of sunrise every day

Explanation: the sun rises every morning at about the same time
The population in a city could change dramatically, what if 10k people moved out of the city in a month?
Your average bank balance could fluctuate as well, what if you spent a lot of money at once?
The population in Los Angeles could change dramatically as well, what if 10k people moved into LA?

Answer 2

Answer:

A. The time of sunrise each day.

Step-by-step explanation:

The sunrise is a perfect example of periodic behavior. The sun rises every morning around 6 am. Whenever you see the sunrise you have a good estimate of what time it is. The sun only rises after a full night proving that it is periodic. Periodic meaning after a certain period of time.  Hope it helped( i tried to give a detailed explanation)