Identify the sentence with a grammatical error.The new employee, along with the rest of the team, were responsible for the project's failure.

The new employee, along with the rest of the team, were responsible for the project's failure.

Having studied English for five years, the grammar rules come naturally to me.

The report, whose findings were groundbreaking, was published in a prestigious journal.

By the time the manager arrived, the employees had been working on the project for three hours.

The sentence with a grammatical error is:

(A) The new employee, along with the rest of the team, were responsible for the project's failure.

Error: The phrase "The new employee, along with the rest of the team," is singular because the subject "the new employee" is the main focus. The verb should be "was" instead of "were" to match the singular subject.

"The new employee, along with the rest of the team, was responsible for the project's failure."