I'm pretty sure it's the last one; Everyone was having a wonderful time at the party, because the present tense helps it feel more active.
Answer:
The answer would be, "To watch it closely over a period of time."
Explanation:
You can get this answer from "monitor" which means <em>to observe and check process of ( something) over a period of time.</em>
I hope this helps!
B. is the awnser i believe glad i could help
