The correct option is C that
Conjunctions are words that link other words, phrases, or clauses together. Subordinating conjunctions are conjunctions that are used at the beginning of subordinate clauses. Some examples of these conjunctions are; although, after, before, because, how, if, once, since, so that, until, unless, when etc.. We use the word 'that' as a conjunction to introduce a subordinate clause to make a statement or provide more information. In the given sentence 'the tree looked like it was on fire 'is a piece of additional information and thus 'that' needs to be used since it is a subordinate clause. Thus Option C is correct.'.And' helps to add one clause or phrase to another similar one. option A is incorrect as the two clauses are not of the similar nature.'.Option B can be ruled out as but is used to introduce a word or phrase that contrasts with what was said before.'Yet' as a conjunction means ‘but’ or ‘nevertheless’. We use it to show contrast. It often occurs after and. Thus Option D is incorrect.