_ Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of portland cement. The component of Portland cement which first hardens is$?

_ Alumina, silica, lime and iron oxide are the basic raw material for

1.	_ Alumina, silica, lime and iron oxide are the basic raw material for the manufacture of portland cement. The component of Portland cement which first hardens is$?
A.	5CaO . 3 Al2O‚Äö√á√â
B.	3CaO . Al2O‚Äö√á√â
C.	3CaO . SiO‚Äö√á√á
D.	2CaO . SiO‚Äö√á√á
Answer» B. 3CaO . Al2O‚Äö√á√â