{1, i, -i, -1} is __________
A. semigroup
B. subgroup
C. cyclic group
D. abelian group
Answer:C
{1, i, -i, -1} is __________
A. semigroup B. subgroup C. cyclic group D. abelian group
Explanation: The set of complex numbers {1, i, -i, -1} under multiplication operation is a cyclic group. Two generators i and -i will covers all the elements of this group. Hence, it is a cyclic group.