singular and plural

She provided (a)/valuable feedbacks (b)/on the presentation. (c)/No error (d)

The company announced (a)/several layoff (b)/due to budget cuts. (c)/No error (d)

The scientist provided (a)/valuable advices (b)/for conducting the experiment. (c)/No error (d)

The chef shared (a)/many recipe (b)/for delicious desserts. (c)/No error (d)

The author wrote (a)/several chapter (b)/for the new book. (c)/No error (d)

She offered (a)/a suggestions (b)/to improve efficiency. (c)/No error (d)

The governments announced(a)/ about the major(b)/ initiatives to tackle social issues. (c)/No error (d)

The manager of the company (a) in the showroom discussed (b)/a new strategies to improve team efficiency. (c)/No error (d)

The organization in the(a)/ southern part revealed (b)/ the downturn due to market fluctuations. (c)/No error (d)

The student submitted (a)/several assignment (b)/for the new course. (c)/No error (d)