Company A has a hosted Direct Connect, a Direct Connect gateway, and a transit gateway in us-east-1. Company B (recently acquired) has multiple application VPCs attached to a transit gateway in us-west-2 in a single account. CIDRs do not overlap. Company A wants to use its existing Direct Connect connection to access Company B's applications from on premises. Which solution will satisfy this requirement?

The correct solution leverages the existing Direct Connect gateway in Company A's account. A Direct Connect gateway can be associated with Transit Gateways in different AWS accounts and regions. By sending an association proposal from Company B's account to Company A's Direct Connect gateway and accepting it in Company A's account, connectivity is established. This allows Company A's on-premises network to reach Company B's applications via the existing hosted Direct Connect connection, Direct Connect gateway, and Company B's transit gateway. Creating a new Direct Connect gateway in Company B's account is unnecessary and would require a new Direct Connect connection or a complex VIF sharing setup, which isn't the most straightforward. Creating multiple virtual private gateways and private VIFs is not scalable and bypasses the benefits of a transit gateway for inter-VPC routing. A transit VIF is used to connect a Direct Connect connection directly to a transit gateway, but the goal here is to connect a transit gateway to an existing Direct Connect gateway, not create a new VIF for Company B's transit gateway.