Why is this the answer?

The answer is stable because this is a very clever word puzzle that changes one word into three different words just by taking away letters. It teaches us how important a single letter can be. Let us look at the first part of the riddle: "As a whole, I am both safe and secure." The complete word is S-T-A-B-L-E, or "stable." When we say a structure is stable, we mean that it is very steady, strong, and not likely to fall down or change. Think of a tall building with a strong foundation; it is stable and feels safe and secure for everyone inside. This is why the whole word fits the first clue. Now, let us try the second part: "Behead me, I become a place of meeting." To "behead" a word means to cut off its head, or the first letter. If you take the letter 'S' from the beginning of S-T-A-B-L-E, you are left with the word T-A-B-L-E, which is a "table." A table is something we use every day! It is a flat, steady surface where families and friends meet to eat meals, work on homework, or play games together. This clue works perfectly and shows how word tricks can be fun. For the third part, we need to "Behead me again, I am the partner of ready." We take the next letter, which is 'T', from T-A-B-L-E. This leaves us with the word A-B-L-E, which is "able." The word "able" means you have the power or skill to do something. When you are "ready and able," it means you are fully prepared to take action. So, "able" is the perfect partner word for "ready." Finally, the riddle says: "Restore me, I become the domain of beasts." If we put all the letters back together, we get S-T-A-B-L-E again. A stable is a type of building used on a farm. It is a home for animals like horses, cows, and other livestock. While the word "beasts" sounds a bit serious, it is just an old-fashioned word for large animals. So, a stable is truly the "domain," or home, of those animals. This clever riddle shows how one word can change its meaning completely with the removal and restoration of just a few letters.