thE nEwly instAllED AlArm systEm, whiCh is DirECtly ConnECtED to thE poliCE, will go oFF iF thE CorrECt sECurity CoDE is not EntErED ______ 60 sEConDs oF touChing thE kEypAD.
A．only
B．unDEr
C．within
D．DirECtly