When Ca(NO₃​)₂​ is heated, it gives CaO, NO₂​(g), and O₂​(g). The correct number of moles of Ca(NO₃​)₂​, CaO, NO₂​(g), and O₂​(g) are present in the reaction are respectively:
a) 1,1,1,1
b) 1,1,2,1
c) 1,1,1,2
d) 2,1,1,1