Which of the following have asymmetric carbon atoms?
1. ClCH_2 – CH_2 Br
2. CH_3 – CHCl_2
3. CH_3 – CH DCl
4. CH_2 Br – CHOH – CH_3
(a) 1, 2, 3
(b) 1, 3, 4
(c) 2, 3
(d) 3, 4