Read the following dialogue between two students, Rina and Lesti:
Rina: 'I'm so anxious about the PTS Sem 1 examination. I've been studying for months, but I still feel uncertain about my preparation.'
Lesti: 'Don't worry, Rina. You've been working hard, and you'll do fine. Just make sure to get plenty of rest before the examination and stay focused during the test.'
What is Lesti's advice to Rina?