Identify the complex sentences in the following:
(a) My father has bought a car. The car is expensive.
(b) My father has bought a car which is expensive.
(c) This is the hospital. I was born here.
(d) This is the hospital where I was born.
Answer Options:

The correct answer is Option D (Only (b) and (d)).

Key Points:
• A complex sentence consists of one independent (main) clause and at least one dependent (subordinate) clause introduced by a subordinating conjunction or relative pronoun/adverb.
• (a) Two separate simple sentences.
• (b) 'My father has bought a car [main clause] which is expensive [subordinate relative adjective clause]' → Complex sentence.
• (c) Two separate simple sentences.
• (d) 'This is the hospital [main clause] where I was born [subordinate relative adverbial/adjective clause]' → Complex sentence.
• Hence, only (b) and (d) are complex sentences.
• Key Takeaway: Sentences containing relative clauses introduced by 'which' or 'where' are Complex Sentences.