(First, I guess you chose the wrong subject since this is English not Physics :p)
Now, the pronouns are words that take the place of a noun.
The Personal pronouns are: I, you, he, she, it, we, they.
I, you, he, she, it are singular; while we and they are plural.
So, in the sentence, we can clearly see the pronoun "we", which is a plural pronoun.
So the plural pronoun in this sentence is We (Answer D)
Hope this Helps! :)
Acceleration is in the direction of motion
Answer: 2 cm
Explanation:
Given , for a converging lens
Focal length : 
Height of object : 
Object distabce from lens : 
Using lens formula:
, we get
, where v = image distance from the lens.
On solving aboive equation , we get

Formula of Magnification :
, where h' is the height of image.
Put value of u, v and h in it , we get

Hence, the height of the image is 2 cm.