The correct answer is 'would pass'.These are the following rules for using appropriate verb forms alongwith the tenses:-Whenever we use Past Perfect (had + Past Participle form of the Verb) in the if clause (Dependent Clause), we have to use would have + Past Tense of the Verb in the Independent clause.For example:- If you had worked hard, you would have got good marks.Whenever we use Simple Past Tense in the if clause (Dependent Clause), we have to use would + Base Verb in the Independent clause.?For example:- If you worked hard, you would get good marks.Thus, if we go by the rule and structure of the given sentence then we have to use would + Base Verb(pass) in the Independent clause.Hence, the correct answer is option 2. The sentence would be: Had she worked hard she would pass.