The most important part about your paragraph is the thesis or the topic sentence. Once you have established this make sure your paragraph always relates back to your topic and make sure to provide examples of your topic. You then want to end your paragraph with a sentence the restates your thesis or topic.
hope that helps a little!
The correct answer is B, because a 'compound-complex clause' consists of two independent clauses (in this case, 1. 'the dog wagged its tail' + AND + 2. '(the dog) barked') and one dependent/subordinate clause ('when I opened the door').
