GMAT Sentence Correction (SC) | Re: Micheaux contends that the guild system both limited and encouraged ex

"who otherwise would have had no support" modifies artisans.

As per the rule, if we set off a modifier by comma then sentence should make complete sense without that modifier because that is non-essential modifier.

Let's try the sentence without this sub-clause

Artisans were allowed to develop their craft, yet, once under
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