Legal Question in Real Estate Law in California

Probably, but the information you're providing is pretty sketchy. For example, whose successor is Mr. A? Mr. X's?

An easement ceases to exist when there is a merger of the dominant and servient properties. If Mr. X granted an easement across Blackacre (which Mr. X owned) to Mr. Y for the benefit of Whiteacre (which Mr. Y owned), and later Mr. X buys Whiteacre, or Mr. Y buys Blackacre, to they become a single property, the easement is extinguished, and upon a subseqent sale of wither to a third party, there is no easement (or at least, the old easement is gone).

However, the scenario you partially describe does not seem to extinguish the easement.

I would also note that easements generally go along with the properties they benefit or burden, especially when they are "easements appurtenant," but this is not necessarily the case, especially with so-called "easements in gross" where there is no dominant (benefitted) property - an example being an easement in favor of the water company for a pipeline.

I hope you don't get paid for your "work in plotted easements," since if you do you should know that your question is impossible to answer with the incomplete information you provide and is therefore nonsense.

I agree with Mr. McCormick on this one, including his sarcastic response. I would have to review the actual easement grants, and the chain of title, to tell you what applies. There are also other considerations.

Answering your question would also require knowing whether the easement is appurtenant, affirmative or negative, or an easement in gross. A transfer of an appurtenant easement to someone who was not in the chain of title to the dominant tenement would be an idle act of nonsense.

Generally easements that are appurtenant transfer with a transfer of the dominant tenement, and do not require a specific separate conveyance. In California, we say that it runs with the land.