Which response includes all of the following

Question

LiOH, KOH, Ni(OH)2, Mg(OH)2, Ca(OH)2
that are insoluble bases, and no others?
1. Mg(OH)2
2. LiOH, Mg(OH)2, Ca(OH)2
3. Mg(OH)2, Ca(OH)2
4. Ni(OH)2, Mg(OH)2
5. LiOH, Ni(OH)2

Answer 1

solubility rules

Answer 2

Ni(OH)2, Mg(OH)2

This is what I think:

Solubility rules say all hydroxides are insoluble except for compounds of Group 1 elements, so LiOH and KOH are not the answer. Calcium is moderately soluble, leaving the other two.