To simplify the expression \((7 - \sqrt{64}) + (6 + 3i)\), we need to simplify \( \sqrt{64} \) first.
Since \( \sqrt{64} = 8 \), we can substitute it back into the expression:
\[ (7 - 8) + (6 + 3i) \]
This simplifies to:
\[ -1 + (6 + 3i) \]
Now, we combine the real parts:
\[ -1 + 6 + 3i = (5) + 3i \]
Thus, the simplified expression is:
\[ 5 + 3i \]
However, since this doesn't match any responses given, there might be an issue or misunderstanding in the initial expression as it reads. Let's confirm the interpretation of the expression in case there were additional details:
Assuming the entire operation was meant to include multiplication or had a different setup, please clarify if the expression should indeed contain any multiplicative components with regards to the parentheses or the context. Otherwise, with the straightforward evaluation, there seems to be a discrepancy between the computed result and the provided options.