D is taller than C and E. A is not as tall as E. C is taller than A. D is not as tall as B. Then, who is the 2nd tallest person?

Let's convert the given conditional sentences into mathematical inequalities:
1. "D is taller than C and E" $⟹D>C$ and $D>E$
2. "A is not as tall as E" $⟹E>A$
3. "C is taller than A" $⟹C>A$
4. "D is not as tall as B" $⟹B>D$

Combining these facts into a single structural height layout:

$$B>D>[C,E]>A$$

From this clear chain, B is the absolute tallest person, and D is firmly positioned as the second tallest person.