Choose the correct option to make one complete sentence without using and, but or so.
The rain came down. All the people ran away.
Topic: Synthesis — subordinate clause of time
Try it
Pick an option and check your answer. The full worked answer is below either way.
Answer
(a) When the rain came down, all the people ran away..
The two sentences are joined by the conjunction WHEN, which makes one a subordinate clause of time and preserves both meanings exactly.
Note that option (d), the participial construction "The rain having come", is also grammatically correct English and is a perfectly good way of combining sentences — but (a) is the more natural and direct rendering, and it keeps "all the people" intact.
Why the others fail: (b) drops "all" and loses the emphasis of the original. (c) is not one sentence at all — two clauses have been run together with no conjunction and no punctuation, which is a comma splice.
When two options are both grammatical, choose the one that changes the original least.
When the rain came down, all the people ran away..