How would I make 1 bool true whilst making others false

I have 3 bools that basically determine a players damage multiplier. I want to make it so that if you check 1 of any of these 3 bools, the other 2 check false.

How would I go about this?

Heres my current code

public bool lvl1_Dmg;
public bool lvl2_Dmg;
public bool lvl3_Dmg;

void Update () 
{
    DMGMulti();
}

 void DMGMulti()
{
        if(lvl1_Dmg)
        {
            lvl1_Dmg = true;
            lvl2_Dmg = false;
            lvl3_Dmg = false;
        }
        else if(lvl2_Dmg)
        {
            lvl1_Dmg = false;
            lvl2_Dmg = true;
            lvl3_Dmg = false;
        }
        else if (lvl3_Dmg)
        {
            lvl1_Dmg = false;
            lvl2_Dmg = false;
            lvl3_Dmg = true;
        }

}

First off, why not use a const array with the values in it?

int[] damageValues = {1,2,3}

Or just use a variable for the multiplier?

int damage = 5

If you really need it, here’s the simpler code:

public bool lvl1_Dmg;
 public bool lvl2_Dmg;
 public bool lvl3_Dmg;
 
 void Update () 
 {
     DMGMulti();
 }
 
  void DMGMulti()
 {
         if(lvl1_Dmg)
             lvl2_Dmg = lvl3_Dmg = false;
         else if(lvl2_Dmg)
             lvl1_Dmg = lvl3_Dmg = false;
         else if (lvl3_Dmg)
             lvl1_Dmg = lvl2_Dmg = false;
 }