The answer is A Depression
The best answer from the choices given would be option A. The luminol test is capable of detecting bloodstains diluted up to 100,000 times. However, the correct value here is 300,000. The luminol test can still read up to that value. Luminol test has found some great application in crime scene investigations. It is able to find traces of blood even if someone has cleaned or removed stains.
Answer: hard water because it has a high concentration of calcium and magnesium
Explanation:
The hardness of water is because of the presence of an appreciable amount of magnesium and calcium in it. These minerals make the water hard. As the hard water contains a high concentration of magnesium and calcium, drinking hard water will increase the daily intake of minerals along with those obtained from food. Hard water is also considered good for the cardiovascular system. Thus the hard water can be considered the best beverage choice.