已知RC≡CH + NaNH2──> RC≡CNa + NH3,炔钠加水又能恢复成炔烃, RC≡CNa + H2O ──> RC≡CH + NaOH,据此可推测酸性大小为:    
 
A、NH3>RC≡CH>H2O  
B、H2O>RC≡CH>NH3
C、H2O>NH3>RC≡CH   
D、NH3>H2O>RC≡CH