As a developer, you have the requirement to access resources in another account. Which of the following is the best way to achieve this?

Answer options:

A.Create a cross-account role and call the AssumeRole API.
B.Create a user in the destination account and share the password.
C.Create a user in the destination account and share the Access Keys.
D.Create an IAM Role and attach it to an EC2 Instance.

Answer - A
The AWS Documentation mentions the following.
For cross-account access, imagine that you own multiple accounts and need to access resources in each account. You could create long-term credentials in each account to access those resources. However, managing all those credentials and remembering which one can access which account can be time consuming. Instead, you can create one set of long-term credentials in one account and then use temporary security credentials to access all the other accounts by assuming roles in those accounts.
All other options are incorrect since the right option is to use cross-account roles.
For more information on Assuming a Role, please refer to the below URL-
https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html