You have an Azure subscription that includes following virtual machines:

VM$1$: A$-$Series Generation $1$ virtual machine that runs Windows Server

VM$2$: A$-$Series Generation $1$ virtual machine that runs Linux

VM$3$: D$-$Series Generation $2$ virtual machine that runs Windows Server

VM$4$: D$-$Series Generation $2$ virtual machine that runs Linux

For which virtual machines you can enable Azure Disk Encryption?