Proponents of artificial intelligence say they will be able to make computers that can understand english and other languages , recognize objects and reason as an expert does-computers that will be used to diagnose equipment breakdowns, deciding whether to authorize a loan, or other purposes such as these.

1) as an expert does-computers that will be used to diagnose equipment breakdowns, deciding whether to authorize a loan, or other purposes such as these
2) as an expert does, which may be used for purposes such as diagnosing equipment breakdowns or deciding whether to authorize a loan
3) like an expert-computers that will be used for such purposes as diagnosing equipment breakdowns or deciding whether to authorize a loan
4) like an expert, the use of which would be for purposes like the diagnosis of equipment or the decision whether or not a loan should be authorized
5) like an expert, to be used to diagnose equipment breakdowns, deciding whether to authorize a loan or not, or the like

[spoiler]OA C, i agree with the answer choice because the parallelism is mantained, but what to know whether "like as expert" correct in sentence construction? and why?[/spoiler]