💡 Detailed Explanation
The correct choice is 'たら' (forming '〜たらどうですか' - how about doing X?). The grammar pattern '[Verb Past Form] + たらどうですか' is a standard way of making a friendly suggestion or recommendation. Sentence translation: 'If your computer is broken, how about trying to ask the shopkeeper?' 'れば', 'と', and 'なら' do not form this idiomatic suggestion construction.