Final answer:
If the weather is below minimums after beginning an approach, the pilot should abort the approach and divert to an alternate airport.
Step-by-step explanation:
If the weather is below minimums after beginning an approach, the correct action would be to abort the approach and divert to an alternate airport. Continuing the approach could be dangerous as the pilot would not have the required visibility and conditions to safely land the aircraft. Going around and trying the approach again may not guarantee better weather conditions, so diverting to an alternate airport is the best option for the pilot's safety.