The correct answer is “The thick German socks were like sheaths of iron halfway to the knees; and the moccasin strings were like rods of steel” and “The old-timer had been very serious in laying down the law that no man must travel alone in the Klondike after fifty below.
Indeed, it is clear that the man has taken all the precautions he thinks are going to ensure his survival in the extreme cold of the Yukon, including “thick German socks” but since he is not a real prospector, he did not take an extra pair with him in case of an accident he also does not heed the advice of the old timer and a real prospector would have done it to make sure that in case of accident or injury someone else would be there to assist.