Not sure but my best guess is to go with B. It just makes the most sense.
The primary source of stem thickening in plants is the vascular cambium. It is a plant tissue located between the phloem and the xylem and in the root of a vascular plant. It is the source of secondary growth or the radial growth of the stem of a plant.
It changes because the age increases
<span>Once the cytoplasm of the amoeba is moving, all the cells in the said cytoplasm will move as well. Consequently all the cell organelles can be seen changing positions. The cytoplasm’s ability to move is dependent on the entire composition of cell organelles that make up the said cytoplasm.</span>
Explanation:
You have 20% of adenine. If you have 20% of adenine than you have 20% of thymine, because the amount of adenine and thymine is equal. 20% plus 20% is 40% of adennine and thymine. From 100% DNA bases subtract 40% and you will get 60%. Then divide this by 2 and you will get 30%. 30% of guanine and 30% of cytosine, because their amounts are equal in the DNA stand.