
Valerie S. answered 05/22/19
Tutor of Many Trades
Adding a comma after "day" would put a break in the sentence at a part where it doesn't make sense to have a break. A comma would make sense after the word "beach" though, as the comma would then be separating two complete ideas.
"There" is in reference to place (the beach, in this case), so "there" is the correct word. "Their" refers to somebody having something, like "their vacation" or "their beach."
So the remaining choice is the answer. This sentence is correct.