Isabel works in an advertising firm. She is required to come up with new catchphrases and slogans for a brand. According to the triarchic theory of intelligence, this situation most likely requires an application of her:

C. creative intelligence

Explanation:

The Triarchic theory of Intelligence as postulated by Robert Sternberg believes intelligence to be about how a person is able to handle and adapt to their surroundings and the changes in it as they go through life.

It is divided into three parts with the relevant part for this question being  Creative / Experiential intelligence. This intelligence refers to the ability to come up with new and different ideas on how to solve something. It is about being able to see a problem in a way no one else does and as such offer a different solution. Essentially, it is to be creative.

Isabel will have to apply her Creative Intelligence to be able to come up with the new catchphrases required as the task requires creativity.

answer; (you have the right of way);

aliens arent real sorry bud