Here are the inferences I drew from the passage:
1. Geoffrey is going to a business meeting or appointment. The passage mentions he is going to his "appointment" and is bringing extra pens and pencils. This implies it is a professional setting.
2. At his appointment there will likely be a speaker or presentation. Geoffrey bringing extra writing tools implies he expects to take notes on whatever is discussed.
3. The appointment does not seem to be for a medical reason or to fill out forms, as those scenarios are not mentioned or implied.
4. Therefore, the most logical inference is that Geoffrey needs the extra pens and pencils to take notes on the speaker, as stated in answer choice b.