Well that answers your inquiry right there - go with the low hanging fruit.

If you need to rationalize it, weed is way safer because you cannot consume a deadly quantity of weed but you can consume a deadly quantity of alcohol. I do not think that you personally would consume a deadly quantity of alcohol, but at least in theory one CAN consume a deadly dose of alcohol but not of weed.

I do not think though that you must rationalize it - you can simply go with the low hanging fruit just because it is a low hanging fruit, period.