A. The wall was climbed over by the thief without being seen.
B. Without been seen, he thief climbed over the wall.
C. The thief was climbed over by the wall without being seen.
D. The wall had been climbed over by the thief without being seen.
There are two phrases in the sentence
- The thief climbed over the wall
- Without being seen
Since the 1st part is our principle phrase and the main action in the sentence is “climbing the wall” so we will focus on the first sentence.
Therefore following justifications of the options are made:
Option A (Correct):
By changing the main phrase “The thief climbed over the wall” we get:
“The wall was climbed over by the thief without being seen.”
Can also be written as:
“The wall was climbed over by the thief, who was seen by no one”
Option B (Wrong):
Here, “without being seen” modifies the thief as he climbs; take the thief out of the picture and that phrase becomes meaningless. Therefore this option is simply an inversion of phrase order not a passive construction. So it is wrong.
Option C (Wrong):
It is wrong because wall cannot climb over the thief
Option D (Wrong):
Here “had been” is used which is wrong. In past Indefinite Tense or Simple Past Tense we always change 2nd form of the verb into was/were + past participle form of the verb.