Let's solve the expression step by step:

$-6 + 5 + (-7) + 4$

1. Start with $-6 + 5 = -1$
2. Then, $-1 + (-7) = -8$
3. Finally, $-8 + 4 = -4$

So, the correct answer is:

D. -4

Would you like a detailed breakdown of how to approach similar problems, or do you have any other questions?

Here are some related questions to explore:

1. How do I simplify expressions with multiple negative and positive numbers?
2. How do parentheses affect the order of operations in arithmetic?
3. What are some strategies for mental math when adding and subtracting integers?
4. How can I apply this to more complex algebraic equations?
5. What is the significance of understanding operations with signed numbers in algebra?

Tip: When dealing with mixed signs (positive and negative), it's helpful to think of subtraction as adding the opposite number.