Micheaux contends that the guild system both limited and

OPTION A - CORRECT
In this option, the part after the colon provides further explanation for the part before colon (The part could be the whole clause OR a part of the clause, even a single word).
The verb for the first clause is 'were allowed' (subject artisans' and that of the second is were discouraged (subject "they").
Thus, this is the correct option

OPTION B - INCORRECT
After Italy, a colon (:) is supposed to follow to show that the clause after it explains the clause before the sentence. However, this option uses a comma (,) which is definitely out of context and changes the meaning of the sentence.

OPTION C - INCORRECT
This option suffers the same fate as option B above because it does't make use of the colon (:) to show expression for previous clause. Rather, it uses a comma (,) which is a punctuation mark to separate list of elements or sentence.

OPTION D - INCORRECT
In this option, there is absolute train wreck. First off "being" should be "they were" . The clause before the comma and the word "but" needs to have a clear verb modifying the subject artisans. The "otherwise not having support" is a phrase referring to the artisans. It does not function as a verb

OPTION E - INCORRECT
The present participle "having no support otherwise" takes up the tense of the verb in the main clause "were". This construction does not clarify that'' not having support'' preceded ''allowing''.