"Soda-line" glass accounts for 90% of the glass produced and can be made by mixing a modifier, or flux, with sand. Which of the following is an example of a soda-line glass modifier?

W) SiO\({}{2}\)

X) Ca(OH)\({}{2}\)

Y) Na\({}{2}\)O

Z) MgO
Y) Na\({}{2}\)O