The correct option is C We weren't told that Miss Shazia is getting married this year.
In Option C, the noun clause "that Miss Shazia... ." functions as a subordinate clause, hence C is the correct option. (Noun clauses function as the subject, object, object of preposition, etc., . Here it functions as an object. Moreover, it does not express a complete thought, hence it is subordinate.)
Option A is a compound sentence, it does not contain a noun clause. 'And' is a coordinating conjunction that has combined these sentences. Since it does not contain the subordinate noun clause, A is incorrect.
Option B has changed in meaning from the original sentences. 'Miss Shazia' performs as the object of the verb "told", which makes no sense here. Therefore, B is incorrect.
Option D has also changed its form, 'this year' has been added to the clause "we weren't told that", saying that "we weren't told" that particular year, whereas 'this year' is regarding "Miss Shazia...getting married." Hence D is incorrect.