What type of error occurs when the user input is ABC in the given code?

When the user input is "ABC" in the given code, it results in a run-time error because the code expects a specific type of input (often a numerical value) and instead receives a string that does not conform to that expectation. During program execution, when the code tries to process this unexpected input, it encounters an issue that prevents it from completing its operation.

Run-time errors occur after the program has been successfully compiled and while it's running, usually due to operations that are illegal based on the input or state of the program. In this case, attempting to use "ABC" as if it were a number (for instance, performing mathematical operations) would lead to a failure during execution, exemplifying a classic run-time error.

Compile-time errors occur when there are syntax issues before the program runs, while overflow errors are specific to situations where the calculated value exceeds the storage capacity of the data type in use. Illegal expressions refer to syntax that cannot be parsed or understood by the compiler or interpreter. In this scenario, the input "ABC" does not trigger those types of errors, but instead disrupts the expected operation of the program at run time.