Do you consider civil disobedience as the only option for protesting unpopular government policies? What other legal actions are available to discontented citizens? What is political efficacy?

According to Thomas Jefferson “…when injustice becomes law resistance becomes duty…” In his ‘Letter from Birmingham Jail’, how did Dr Martin Luther King Jr. justify civil disobedience? Do you consider civil disobedience as the only option for protesting unpopular

government policies? What other legal actions are available to discontented citizens? What is political efficacy?