An abstract class in C++ can have both abstract methods (methods without any definition) and concrete methods (methods with a definition). This allows for a mix of defined and undefined behaviors in subclasses.

In C++, the catch keyword is used to define a block of statements that will be executed when a particular exception is thrown. This block is used to handle the exception and provide a response, ensuring that the program can continue or terminate gracefully.

A stack overflow error typically indicates that there's too much recursion, causing the system's stack to exceed its capacity. One effective way to resolve this is by converting the recursive algorithm to an iterative process using loops, which can help manage the stack better and prevent such errors. This retains the logic without heavily depending on the system's stack.

In tail recursion, the function's recursive call is the last action executed. The significance of tail recursion is that the current function frame can be discarded before the recursive call is made, potentially allowing compilers to optimize the recursion by reusing the current function's stack frame for the next.

To determine if a year is a leap year, we need to check if the year is divisible by certain numbers. The modulus operator (%) gives the remainder of a division and can be used to check for divisibility. The equality operator (==) is used to check if the remainder is zero. Hence, the combination of % and == is crucial to check the divisibility conditions required to determine a leap year.

Declaring a function as a friend within a class gives that function the ability to access the class's private and protected members. However, it doesn't make that function a member of the class. A friend function remains a non-member function, but it's just granted special access privileges.

Abstraction allows for simplifying complex reality while exposing only the necessary parts. By abstracting the concept of a shape, each specific shape (like Circle, Rectangle, Triangle) can implement its drawing method while adhering to a common interface or abstract base class.

While getter and setter methods might introduce a slight overhead, modern compilers can inline these functions to ensure minimal performance impact. By encapsulating data, you enhance the maintainability and structure of the code.

The break statement is primarily used for exiting a loop or a switch when a specific condition is met. In a professional codebase, it's particularly useful for scenarios where processing should not continue once a certain condition has been satisfied, ensuring efficient and intended behavior.

In C++, when multiple 'if' conditions are true, only the block corresponding to the first true condition will be executed. Subsequent true conditions are ignored.

The 'git push' command is used to upload the local repository to a remote repository on a cloud platform. It sends local changes to the remote repository, keeping them in sync.

The correct option is amend. The git commit --amend command allows you to modify the most recent commit message. It opens the default text editor for you to make changes. This is useful when you need to fix a typo or provide additional information to the commit message without creating a new commit.