Show this language is non-regular using pumping lemma: B = {ww | w ∈ {a,b,c,...,z)*}
Your proof using the pumping lemma is wrong. You choose a pumping lemma constant $p=4$ but what happens if $p=5$ works? The pumping lemma tell us that there exists a constant $p$. Now you have to try all the remaining possible values of $p$.

I recommend you to study carefully the pumping lemma first. It is a bad idea to try using it without understanding it. After that if you want to assimilate it more you can check this answer: https://cs.stackexchange.com/a/50618/31129 where I explain some common mistakes.