Choose the CORRECT statement regarding convolutional layer

Choose the CORRECT statement regarding convolutional layer

A convolutional layer must set stride$=1$

A convolutional filter larger than the size $2$x$2($including $2$x$2)$ always decreases the resolution of feature map as output

A convolutional layer with stride$>1$ can increase the resolution of output feature map

A convolutional filter with the size $1$x$1$ can sometimes increase the resolution of feature map as output compared with the input one.