In new global markets, Under Armour wants to focus on line extension to leverage their existing brand name and market strength. In Brazil, Under Armour's apparel and shoes are already big sellers and the only categories where they currently offer products. Two new product lines are under consideration to serve the large population of martial arts practitioners there. One is a line of moisture-wicking compression shirts with extra strong stitching for durability. Another is a line of punching bags and punching mitts.

The question is not complete, however, i think the concluding part of the question should be:

"What product line should Under Armour pursue?"

The answer to that Under Armour should pursue their new line of compression shirts.

Explanation:

Comparing the two new product lines, that is, moisture-wicking compression shirts with long stitching for durability and punching bags and punching mitts, it can be observed that:

The punching bags and punching mitts product line is for a niche population of users in the market, while the compression shirts will be usable by all the population within the market. The moisture-wicking compression shirts have a specific advantage of durability, because of this factor, customers will be eager to try out this new product with cool features. While the punching bags and mitts are just like that of any product in the market space.

Therefore, Under Armour will be wise to pursue the product line of the moisture-wicking compression shirts.