Question ID:PT20 S4 Q11 Passage:John works five days each week except when on vacation or during weeks in which national holidays occur.  Four days a week he works in an insurance company; on Fridays he works as a blacksmith.  Last week there were no holidays, and John was not on vacation. Therefore, he must have worked in the insurance company on Monday, Tuesday, Wednesday, and Thursday last week. Stem:Which one of the following is an assumption on which the argument depends? Correct Answer Choice:DChoice A:John never takes a vacation of more than one week in length. Choice B:Every day last week that John worked, he worked for an entire workday. Choice C:John does not take vacations in weeks in which national holidays occur. Choice D:Last week John worked neither on Saturday nor on Sunday. Choice E:There were no days last week on which John both worked in the insurance company and also worked as a blacksmith.