Question

Combine the following sentences into a complex sentence with a subordinate adverb clause:
The rains had started the mud slides. The homes were not safe to live in. [Advanced]

• A. The homes were not safe to live in because the rains had started the mud slides.
• B. The rains had started the mud slides, so the homes were not safe to live in.
• C. The rains having started the mud slides, the homes were not safe to live in.
• D. The rains which started the mud slides made it difficult to live in the homes coming under it.

Answer 1

The correct option is A The homes were not safe to live in because the rains had started the mud slides.

An adverb clause is a subordinate clause which does the work of an adverb .It may, therefore, modify some verb, adjective, or sometime another adverb in the main clause.
In this case,
Option A is correct. The homes were not safe to live in is the principal clause and since the subordinate clause because the rains had started the mud slides, acts as an adverb by modifying the verb 'safe' in the principal clause, it's called a subordinate adverb clause.
Option B is incorrect as the sentences have been joined into a compound sentence. The coordinating conjunction 'so' has been used.
Option D is incorrect because the sentences have been joined by using an adjective clause where 'the rains' have been qualified.

Option C is incorrect as the sentences have been joined into a simple sentence. It is devoid of any subordinating conjunction.