Take a look at the item again:
Circling the parking lot, (A)
Dominique searched for an empty space close to the mall
entrance (B)
so that an afternoon thunderstorm wouldn't drench
her (C)
while she was loaded down with good buys.
You wanted to do this:
Circling the parking lot, Dominique searched for an empty space close to
the mall entrance. So that an afternoon
thunderstorm wouldn't drench her while she was loaded down with good buys.
Adding a period after entrance makes a fragment. So that an afternoon thunderstorm wouldn't drench her ... is a subordinate clause. This type of clause cannot stand alone as a complete sentence.
You might want to review the rules.
Go back to the sentence to try again.