4. which of the following group has a proper subgroup that is eyclic (a) z15 x z17 (b) s3 c)(z, +) goval d) (q+)

all option are correct . option a - take (Z15,I) is proper subgroup of Z15×Z17 option b - take T={ e , (12) } is proper subgroup of S3 option c - take 2Z option d - take (z,+...