💡 Detailed Explanation
'～とあれば' means 'if it's for the special reason/case of...'. It is used to introduce a special condition that justifies a strong action or resolution that follows. Here, the special reason 'for my beloved family' justifies the strong resolve 'to take on any difficult job'. 'とすれば' and 'としたら' are for general assumptions ('assuming that...'). 'とあって' gives a reason for a resulting state or event that has already occurred, not for a future intention or resolve.