You are creating a Cloudformation template in which Userdata is going to be passed to underlying EC2 Instance. Which of the below functions is normally used to pass data to the UserData section in the Cloudformation template?

Answer options:

A. "UserData": {"Fn::Base64": {
B. "UserData": { "Fn::Ref": {
C."UserData": { "Fn::GetAtt": {
D."UserData": { "Fn::FindInMap": {

Answer – A
The AWS Documentation mentions
The intrinsic function Fn::Base64 returns the Base64 representation of the input string. This function is typically used to pass encoded data to Amazon EC2 instances by way of theUserData property.
For more information on the Fn::Base64 function, please visit the below URL:
http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/intrinsic-function-reference-base64.html