To add the polynomial expressions \( 3 - 2p - 5p^2 \) and \( p^4 - 3p + 4 \), we first write them together:
\[ (3 - 2p - 5p^2) + (p^4 - 3p + 4) \]
Next, we can rearrange the terms by their degrees:
\[ p^4 - 5p^2 - 2p - 3p + 3 + 4 \]
Now, combine like terms:
- The \( p^4 \) term is: \( p^4 \)
- The \( p^2 \) term is: \( -5p^2 \)
- The \( p \) terms are: \( -2p - 3p = -5p \)
- The constant terms are: \( 3 + 4 = 7 \)
Putting it all together, we get:
\[ p^4 - 5p^2 - 5p + 7 \]
Thus, the final result of the addition is:
\[ \boxed{B. , p^4 - 5p^2 - 5p + 7} \]