Final answer:
The complex sentence in the given options is: O They might have the meeting on Tuesday, or they might have it on Thursday instead.
Step-by-step explanation:
The complex sentence in the given options is:
O They might have the meeting on Tuesday, or they might have it on Thursday instead.
A complex sentence is a sentence that contains one independent clause and at least one dependent clause. In this sentence, 'They might have the meeting on Tuesday' is an independent clause, and 'they might have it on Thursday instead' is a dependent clause introduced by the subordinating conjunction 'or'.
Learn more about identifying a complex sentence in a given set of options