Classifying sentences can be difficult. There are many types of sentences. They include simple sentences, compound sentences, complex sentences as well as compound-complex sentences. Depending on the content of the sentence, it is classified into different groups. In this case, this sentence is a complex sentence. It is highlighting the role of Marcia in her class and at the same time is also asking a question.
You need to learn to use these sentences to ensure their proper use in a conversation. Once you practice their use, you can easily implement them in your usual conversation for better language skills.