Final answer:
The correct statements about polyatomic ions are that they always have a charge and are composed of more than one atom, making option D ('Both A and B are correct') the correct choice.
Step-by-step explanation:
The student has asked which statements are true about polyatomic ions. After analyzing the options presented, we can confirm that the correct answers are that polyatomic ions always have a charge (A) and are always composed of more than one atom (B). Therefore, the correct response to the question is 'D. Both A and B are correct'. It's important to recognize that polyatomic ions can indeed be found in nature, which makes option C incorrect. For example, the nitrate ion (NO3−) is a well-known polyatomic ion with a charge of -1 and is composed of one nitrogen atom and three oxygen atoms.