Here are the answers to the provided questions:
Question 1: Gretta is MOST likely performing crunches.
Question 2: Ren is MOST likely performing a bridge.
Question 3: The exercise that BEST fits Silvia's needs is the bird dog.
Question 4: Levar is MOST likely doing mountain climbers.
Question 5: The type of exercise that will MOST likely help Irene achieve her goal is flexibility exercises.
Question 6: This scenario BEST demonstrates the principle of progression.