Which one of the following statements is correct?
(a) Reciprocating compressors are used to supply large quantities of air at a lower pressure ratio.
(b) Centrifugal compressors are used to supply large quantities
(c) Centrifugal compressors are used to supply small quantities of air at a lower pressure ratio
(d) Centrifugal compressors cannot be rum at high speed because of impeiler, diffuser and casing.