You need to configure VNet Peering between the two networks. The questions states, "The solution must ensure that virtual machines connected to VNET1 can communicate with virtual machines connected to VNET2". It doesn't say the VMs on VNET2 should be able to communicate with VMs on VNET1. Therefore, we need to configure the peering to allow just the one-way communication.
1. In the Azure portal, type Virtual Networks in the search box, select Virtual Networks from the search results then select VNET1. Alternatively, browse to Virtual Networks in the left navigation pane.
2. In the properties of VNET1, click on Peerings.
3. In the Peerings blade, click Add to add a new peering.
4. In the Name of the peering from VNET1 to remote virtual network box, enter a name such as VNET1-VNET2 (this is the name that the peering will be displayed as in VNET1)
5. In the Virtual Network box, select VNET2.
6. In the Name of the peering from remote virtual network to VNET1 box, enter a name such as VNET2-VNET1 (this is the name that the peering will be displayed as in VNET2).
There is an option Allow virtual network access from VNET to remote virtual network. This should be left as Enabled.
7. For the option Allow virtual network access from remote network to VNET1, click the slider button to Disabled.
8. Click the OK button to save the changes.
Reference:
https://docs.microsoft.com/en-us/azure/virtual-network/virtual-network-manage-peering

Reference:
https://docs.microsoft.com/en-us/azure/automation/automation-update-management

You can change an existing playbook in Security Center to add an action, or conditions. To do that you just need to click on the name of the playbook that you want to change, in the Playbooks tab, and Logic App Designer opens up.
Reference:
https://docs.microsoft.com/en-us/azure/security-center/security-center-playbooks