(b) Yes, that's correct. As regards the question what rules or national law will apply in the event of disputes where more than one legal system is potentially involved, the same principles apply to all contracts, including online contracts

There are two things to consider. One is whether the terms of the agreement refer to particular agreed rules for resolving disputes, or to a chosen system of national law. If no agreed provisions exist, the general rule is that the applicable law will be that of the country with which the transaction has its closest connection. This is a question to be determined as a matter of fact, taking into account things such as where the parties were at the time of the transaction, where the transaction came into existence, the location of the things transacted for at the time of transacting, and the place of performance.

It can be hard to predict what conclusions will be reached on this question in particular cases and for that reason it is common to find that online transactions contain agreed rules for resolving disputes.