Can someone please explain the Exception flow quiz to me?

I've added some comments to the code block that hopefully help to explain

print("A")                  # prints the character 'A'
try:                        # opens a try block
    result = "test" + 5     # adds a string to an int, this throws a TypeError
    print("B")              # gets skipped, we go straight to the except block
except ValueError:          # we didn't get a ValueError (we got a TypeError)
    print("C")              #  so this gets skipped too
except TypeError:           # we arrive here right after result = string + int
    print("D")              # prints the character 'D'
else:                       # the else block only executes if no exceptions occured
    print("E")              # we had a TypeError so this is skipped
print("F")                  # prints the character 'F' (not part of the try block)

Usually, when something goes wrong Python raises an exception - an error that describes what went wrong. When a try block is opened, if any statements within it raise an exception (like a ValueError, TypeError, KeyError, etc) then Python checks to see if there's an except block that matches that exception type, if there is it executes that block instead of doing what it normally would (it would normally terminate your program and print the error).

Sometimes we might want python to continue even if there's an error, or we might want a very specific way of handling that error. For instance, say we're looking up an item in a dictionary, we get the dictionary key from the user and return the value associated with that key, but if the user enters a key that's not in the dictionary we'll get a key error. Crashing here isn't very user friendly, so instead we use a try/except Key Error block to let the user know the value couldn't be found (and maybe giving them another go) instead of the program terminating.