Do you have any examples, or could you type things up a little better. Without that, I’m not too sure if anybody can really answer.
Answer:
C) A career in politics, which was not his first career, ended up being the ticket to success for Abraham Lincoln.
Explanation:
In the sentence shown in the question above, the information considered to be non-essential is "... which was not his first career ..." This statement is considered non-essential because it is not necessary for us to understand the context of the sentence and the message that must be passed. This type of information must always be accompanied by two commas, one at the beginning of the information and one at the end, as shown in option C.
It is not correct to use the symbol ";" in place of the comma, in this case, since this symbol should not be used to separate non-essential information.
Hi Adam are you going to the park on Saturday? No, I'm not, I am playing basketball at school. Want to go to the shopping mall in the morning? Wait you changed the sentence?