The correct answer is: B. Only assumption II is implicit.
The statement “The office building needs repairing just as urgently as it needs internal as well as external painting” does not provide enough information to support assumption I. It is possible that the efficiency of people working in the office could be improved without repairing the office building. For example, the office building could be cleaned and organized, or new equipment could be purchased.
However, the statement does support assumption II. Repairing and painting an office building are both costly endeavors. The statement indicates that the office building needs both repairs and painting, so it is reasonable to assume that the company will need to spend money on these projects.
Therefore, only assumption II is implicit in the statement.