From the additive group ℚ to which one of the following groups does there exist a non-trivial group homomorphism?
1
ℝ×, the multiplicative group of non-zero real numbers
2
ℤ, the additive group of integers
3
ℤ2, the additive group of integers modulo 2
4
ℚ×, the multiplicative group of non-zero rational numbers