Over the years, these sayings have become a ritual
in the course of eating a meal. Think of it as a Japanese way of prayer.
By itself, "Itadakimasu!" is said to express appreciation for the meal prepared. But when directly translated, it is more like "Now I'm going to dig-in!" in English.
As for "Go-chiso-samadeshita!", spoken after the meal, it is said to express gratitude for the wonderful meal and for the hospitality of the person who prepared them.
The answer choices are...
1) Eat the side dishes until cleared, move on to rice, then drink the soup last.
2) Eat from the biggest plate to the smallest.
3) Sip a bit of soup as a starter, then keep on eating all dishes simultaneously.
4) None of the above