The correct answer is option (1) because Statement I is correct which states that RNA interference takes place in all eukaryotic organisms as method of cellular defense and Statement II is incorrect which states that RNAi involved the silencing of a specific mRNA due to a complementary ssRNA molecule that binds and prevents translation of mRNA. In statement II, it should be complementary dsRNA molecule that is involved in silencing of a specific mRNA. Options (2), (3) and (4) are incorrect as they represent wrong answer.