2. which is not one of the three kinds of rocks?

2. which is not one of the three kinds of rocks?
Answer
Brief Explanations:
The three main types of rocks are igneous, sedimentary, and metamorphic. We need to identify the option that is not one of these.
Answer:
Since the options are not clear - if one of the options is something other than igneous, sedimentary, or metamorphic, that would be the answer. Without legible options, we cannot provide a definite answer. Please clarify the options.