Which of the following is not a possible effect of rising carbon dioxide levels on plants?
a.
increased photosynthesis
b.
increased plant mortality
c.
increased crop productivity
d.
increased plant growth

increased plant mortality

Explanation:

The rise of carbon dioxide in the atmosphere  will definitely bring about increased in photosynthesis.

Photosynthesis in plants is a process whereby green plant produces nutrient in the present of sunlight from carbon dioxide and water. Photosynthesis is a necessity for plants to supply nutrient to the plants . The chemical equation for photosynthesis  can be represented as follows:

6CO2 + 6H2O sunlight → C6H1206 + 6O2

Photosynthesis converts light energy into chemical energy. Green plants in the presence of sunlight uses CO2 and H2O to produce food. Increase carbon dioxide will definitely increase crop productivity and plant growth. The more the carbon dioxide and water in the presence of sunlight  nutrient are added to the plant.

Plant will definitely not die because of rise in CO2.  

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

gold i'm pretty sure i might be wrong