<h3>The blood in the pulmonary artery is going to the heart to collect oxygen, and therefore has a low content of oxygen. So, the blood in the pulmonary artery is a violet colour because it has low oxygen. The blood in the pulmonary vein is oxygen rich, and so it gives a scarlet</h3>

The defendant is the person or organization with which an action is being brought against. For example: a man rear-ends a woman in a car accident. The woman can file a lawsuit to recover (get) money from the man for her medical injuries and damage to her car. The woman is the plaintiff suing the man who is the defendant.
Having a credible and reliable sources are important in performing research especially on the internet. This is because nowadays with just one click all information can be check on the internet however one is not sure if that is the right one that can then be validated thus there are strategies to know information if they are credible and reliable. One of it is the site one knows and trust mostly is important as it can help narrow down what you're looking for. Another would be checking on the date, select the latest one for it to be more reliable. Another would be checking the credentials for the writer as for you to be sure information provided is credible and lastly check if there are comments such as reviews from the source and the author to make sure that other people are also using the information provided which means it is reliable.
I think your answer for this question is D . I may be wrong ... but I think it's D