Consider the following statements
(1) The only practical way of improving efficiency of Otto cycle is to increase the compression ratio of an internal combustion engine
(2) Ericsson cycle needs heat transfer in all the processes
(3) Ericsson and Stirling cycles employ regenerative heat exchangers for reversible heat transfer
(4) Atkinson cycle has a greater specific work than a comparable Otto cycle engine which of the above statements are correct?
(a) 1, 2, 3 and 4 (b) 1, 2, and 4 only
(c) 2, 3 and 4 only (d) 1, 2, and 3 only