Final answer:
The punctuation error in the sentence is option B) 2.
Step-by-step explanation:
The punctuation error in the sentence is option B) 2.
The error is the comma after aged and before therefore. This is a comma splice, which occurs when two independent clauses are joined together with a comma instead of a coordinating conjunction or a semicolon.
To correct this error, the sentence can be rewritten as:
The lobbyists' spent a great deal of time, effort, and money educating the legislators about the problems of the aged; therefore, the bill passed without difficulty.