Depends on 'factors.' Exposing it at 100 will give good results in virtually all cases, so it's a safe bet. How you develop it is up to you to decide. Some people like punchy negatives, some like them flatter. So some people will expose this film at 100 and develop the heck out of it, while others will go with a compensating developer that compresses the curve and give gentle development only. It's virtually a religious choice which route you take.
If you expose at 100 and then use the normal (200) development times indicated by Foma as
@Nitroplit suggests, you will get usable negatives for all intents and purposes. Can't go wrong with that approah