Which operator would you use to remove an element from an array in a document?

The $pop operator is specifically designed to remove an element from an array in a document. It can remove the last element or the first element of the array, based on the value specified. When you use $pop with a positive value (1), it removes the last item, while using it with a negative value (-1) removes the first item from the array. This makes $pop the ideal choice for directly manipulating the elements within an array without the need for complex queries or filtering.

The $set operator is used to assign a new value to a field in a document, but it does not specifically focus on removing elements from arrays. Similarly, $addToSet is used to add an element to an array only if that element does not already exist in the array, which also doesn't involve removal. The $push operator, on the other hand, appends an element to the end of an array, which is the opposite of what is needed for removing elements. Thus, among the given options, $pop clearly stands out as the correct operator for removing elements from an array.