Which figure should replace the question mark (?) if the following figure series were to be continued?

Correct option is D

Logic: (1^st figure to 2^nd and 3^rd figure to 4^th is same) and (2^nd figure to 3^rd figure and 4^th figure to 5^th figure is same)
Red color shows posion of K changes.
Green color is shows position of U changes
Blue color is shows interchange L,O and this position.
This type of letters are in only option d . so answer is option d (no need to check further after found one different answer throughout all the options)