The correct answer is option B. A and B only
In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.
Chromosomes are not visible in the cell’s nucleus—not even under a microscope—when the cell is not dividing. However, the DNA that makes up chromosomes becomes more tightly packed during cell division and is then visible under a microscope. Most of what researchers know about chromosomes was learned by observing chromosomes during cell division.
Two objects that are similarly charged will repel, while two objects with opposite charges will attract. Moreover, a neutral object will attract either charges.
Answer:
"Manganese is a grey-white, hard and very brittle metal.
It tarnished on exposure to air and oxidized to manganese when heated."
Credits to: Yahoo