Why is the convolutional layer important in convolutional neural networks?

Because a convolutional layer would make the model overfit the training data so that it generalizes better

Because convolutional neural networks are unsupervised deep learning models and therefore, a convolutional layer helps the model betterfit the data

Because if we do not use a convolutional layer, we will end up with a massive number of parameters that will need to be optimized and it will be super computationally expensive

Because convolutional neural networks take flattened images as input and therefore the convolutional layer helps the model regenerate the input images

None of the above