You may create a new vApp under which of the following conditions (Choose Two):

A.
The ESX Server can be version 3. 0 or later

B.
The ESX Server hosting the vApp must in a DRS-enabled Cluster

C.
The ESX Server must be version 4.x

D.
The ESX Server can be a standalone host or to side in a DRS Cluster

Explanation:
http://www.vmware.com/pdf/vsphere4/r41/vsp_41_vm_admin_guide.pdf
Create a vApp
After you create a datacenter and add a clustered DRS-enabled host or a standalone host to your vCenter Server
system, you can create a vApp.
You can create a vApp under the following conditions.
n A standalone host is selected in the inventory that is running ESX 3.0 or greater.
n A DRS-enabled cluster is selected in the inventory.
You can create vApps on folders, standalone hosts, resource pools, DRS-enabled clusters, and within other
vApps.
Procedure
1 Start the New vApp Wizard on page 130
The New vApp wizard allows you to create a vApp.
2 Name the vApp on page 130
The name that you enter is the vApp display name that appears in the inventory.
3 Select the vApp Destination on page 131
The destination is the standalone host, cluster, resource pool, or another vApp on which the vApp will
run.
4 Allocate vApp Resources on page 131
Determine how CPU and memory should be allocated for the vApp.
5 Complete the vApp Creation on page 131
The Ready to Complete page lets you review the vApp configuration.