Select the segment of the sentence which has an Adjective clause:

where the car had met with an accident

The correct answer is Option (4) → where the car had met with an accident

• An Adjective Clause is a dependent clause that modifies a noun and usually begins with relative pronouns (who, whom, whose, which, that) or relative adverbs (where, when, why).
• In the sentence, "where the car had met with an accident" acts as an adjective clause because it describes "the spot" (a noun), telling which spot is being referred to.
• "Where" functions as a relative adverb, introducing the clause.

OTHER OPTIONS

 "I had just gone a short distance" – This is an independent clause (main sentence).
  "when I came on the tracks and" – This is an adverbial clause (tells when something happened).
  "had no difficulty in finding the spot" – This is part of the main clause and does not contain an adjective clause.