Which of the following operators would be used to negate a query condition in MongoDB?

The use of the $not operator in MongoDB is specifically designed to negate a query condition. When constructing a query, using $not allows you to exclude documents that meet a specified condition. For example, if you want to find documents where a field does not equal a certain value, you can apply the $not operator to that condition.

This operator is particularly useful in scenarios where you want to filter out documents based on specific criteria while ensuring that only those documents that do not satisfy the condition are considered in the result set.

For instance, the following query retrieves documents where the "status" field does not equal "active":

db.collection.find({ status: { $not: { $eq: "active" } } })

In this case, the $not operator effectively negates the $eq operator, leading to the desired outcome of fetching documents with any status other than "active."

The other operators do not serve the same negation purpose: $nor is used to combine multiple conditions, $ne is utilized for not equal comparison without negation, and $eq means equal, which is the opposite of negating a condition.