What is an important waste product that plants produce during photosynthesis and is needed by other organisms?
O water
O oxygen
O carbon dioxide
0 hydrogen

Oxygen is formed as the waste product. Some is used for respiration by the plant. The excess is released from the leaves, making it available for respiration to animals and many microorganisms. During the light, provided the rate of photosynthesis is sufficiently high, plants, give out oxygen.

Explanation:

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

the answer is a and have a great day