It was actually "weaker immune system". Just took the test and got it right.
Explanation:
All the other answers are short term effects. If you don't sleep for a day, your movements would be slower, you would be more tired and wouldn't be able to concentrate. However, if you just miss one day of sleep, your immune system ain't gonna suffer.
"Defensive driving means protecting yourself from more than just other drivers. It's about thinking ahead and anticipating hazards so you can avoid accidents before they happen."
