Which of these statements most accurately describes how carbon dioxide enters a leaf?
a. co2 is carried by water in leaf veins.
b. co2 is pulled in by leaf veins.
c. co2 diffuses by way of the stomata.
d. co2 enters a leaf through osmosis.

CO2 diffuses by way of the stomata (ans C)

Explanation:

On the surface of the leaf there are tiny pores are present known as Stomata and CO2 from the air diffuses to the plants through the tiny pores (stomata).

Stomata let CO2 reach the others cells in the leaves and make carbohydrates, this process is known as photosynthesis.

Photosynthesis is the process in which energy comes from sun light turns into chemical energy.

i think the answer is b.