In triangle ABC, if $\angle B = 90°$, $\angle A = 60°$ and $BD \perp AC$, then

1. $\angle CBD = 60°$
2. $AD : AB = 1 : 2$
3. $\mathrm{△}ABD$ and are similar to each other.

• ai and ii
• bi and iii
• cii and iii
• di, ii and iii