We have a $326$x$326$ image. After first convolutional layer $($without zero padding$)$ and after $2$x$2$ max pooling, the size of image is $160$x$160.$ What was the size of

filter $($kernel$)?$

O $7$x$7$

O $3$x$3$

$5$x$5$

$9$x$9$