Because people are sad and angry and just want to let everything out.
OR
They want attention
Answer:
wrong, it's D. deoxygenated blood has lower levels of oxygen inside of it compared to oxygenated blood
Explanation:
Deoxygenated blood is blood with low levels of oxygen that flows toward the heart. Oxygenated blood if blood with high levels/exposure to oxygen that flows away from the heart.
Although A is true, it doesn't explain the difference, more like a fact.
B. The answer is shiver because our body creates heat when we shiver.