The correct answer is: B. The gardener forbade the boys to pluck the flowers.
The gardener used the imperative mood, which is used to give commands or instructions. The word “forbade” is a synonym for “ordered” or “commanded.” In this case, the gardener is ordering the boys not to pluck the flowers.
The other options are incorrect because they do not accurately reflect the gardener’s statement. Option A is incorrect because the gardener did not say that the boys should not pluck flowers, he forbade them to do so. Option C is incorrect because the gardener did not tell the boys that they should not pluck flowers, he ordered them not to do so. Option D is incorrect because the gardener did not scold the boys for plucking flowers, he forbade them to do so.