Let's check assumption I: It need not necessarily be true. A subjective (written or long-form) paper could be used at present. Hence, assumption I is not implicit. 

Let's check assumption II: Since the chairman of the committee is doing an act with a certain purpose, that is, to improve the examinations, the committee must also aim to improve the admission exams, or else there would be little use in introducing objective-type tests. Hence, assumption II is implicit. 

Therefore, Option B is the correct answer.