Are Clothing advertisements aimed at teenagers effective? And, are they ethical conclusion?

It depends on the advertisment.

Usually adds aimed at teens will be effective because the ads will look trendier.

Clothing advertisements that you see on television are probably not the most effective just because they're family clothing that teenagers are not so interested in. (Old Navy, JC Penny etc) Teenagers are more interested in what pop stars and celebrity styles, like the brand Kendall and Kylie. I say no, they're not an ethical conclusion.