In which of the following reversible gas reactions does the value of \(\rm K{p}\!=\!K{c}\) (read as: K sub P equal K sub C):

W) A + B \(\leftrightarrow\) C (read as: A plus B, double arrow, yields C)

X) 2A + B \(\leftrightarrow\) C + D

Y) A + B \(\leftrightarrow\) C + D

Z) A \(\leftrightarrow\) B + C
Y) A + B \(\leftrightarrow\) C + D