Answer:
"Nighttime leg cramps frequently occur in calf muscles." is a complete sentence.
Explanation:
"Displays her most prized possessions in the living room" is not a complete sentence.
Who's displaying the possessions? Who is "she" referencing to? There should be a person's name in front of the word displays.
For example, "Claire displays her most prized possessions on the mantel in the living room." Adding a name to the beginning of the sentence would make it complete.