Which word in the sentence is a direct object?

a grapefruit tree can produce 1,500 pounds of fruit each year.

a.
pounds

b.
year

c.
tree

Let's go through each answer. 

A.
This is incorrect because it's a measurement not a direct object.

B.
This is also incorrect for the same reason, it's a measurement, not a direct object. :)

C.
This is correct because it's an object. :)

The answer is C.

Hope this helped! If you have anymore questions or don't understand, please comment on my profile or DM me. :)

For example. if i walk 10 feet north then go 20 feet east that would be a displacement of around 15 feet