It’s the letter C.................
<span>Helium nuclei have a positive charge of 2+ when observed. Compared to a hydrogen nuclei, we can see that the Helium nuclei is more difficult to fuse as it has a greater charge than Hydrogen 1+. This chemical difference makes the answer true.</span>
Answer:
The first line of defence (or outside defence system) includes physical and chemical barriers that are always ready and prepared to defend the body from infection. These include your skin, tears, mucus, cilia, stomach acid, urine flow, 'friendly' bacteria and white blood cells called neutrophils.
Explanation:
Hormone Signaling. The glands of the endocrine system secrete hormones directly into the extracellular environment. The hormones then diffuse to the bloodstream via capillaries and are transported to the target cells through the circulatory system.
