Week's question

Let C = { abcd, bcdef, afghijk, bcdgh, ghijk }. Choose the alternative that contains all the sets of twins from C:

1) abc, gh, ijk
2) bcd, ef, hij
3) bcd, gh, ghi
4) bcd, gh, ijk
5) None of the above

Author: Victor de Abreu Iizuka
Translated by: Rafael S. Padilha