<em><u>The correct answer is the following:</u></em>
<em>Question 2: option B,</em> "Carmina chose to pursue the following sports: track, gymnastics, and ice hockey."
<em>Question 3: option C</em>, "I live my life by this motto: "Live life to the fullest"."
In the first question, the colon is used to introduce a list of items, in his case the sports that Carmina has chosen to pursue. But before the colon there has to always be a full sentence, that is why option B is the correct answer.
In the second question, the colon is used to emphasize a phrase or a word at the end of a sentence. Again, because of this, option C is the correct answer, as "I live my life by this motto" is a full sentence that has meaning by itself.