You are thinking of building multiple campaigns based on the following native targeting variables:- Job-...

You've built audiences, but they are too small for the product launch. The only way to expand an audience is to take out segmentation variables. 

In this case, think of the variables that have less to do with the segment. This can be very tricky questions in the exams as sometimes it’s objective and with experience, you will see what interests work better than others. 

However, let's categorize the segmentation variables into the following groups:

Important variables: marathon and triathlon, mobile and operating system, and income.

Semi-important: Luxury travel.

Least-important: job, age of children in household.

Think about it; the smartwatch is a high-end gadget for hardcore sports fans. They also need to have a mobile phone due to the new mobile application for the smartwatch. So you definitely want to leave all of the variables in the "important" bucket.

Luxury travel could help you better segment high-end users, but it's not imperative. Job and age of children in household, in this case, are irrelevant.