A company uses the Simple Notification Service to send notifications to various subscribers for their service. There is a user requirement for the subscriber only to receive certain types of messages and not all messages published to the topic. How can you achieve this?

Answer options:

A.By adding a filter policy to the topic subscription
B.By adding an IAM policy to the topic
C.Publish the messages to an SQS queue
D.Publish the messages to a Lambda function

Answer - A
The AWS Documentation mentions the following.
By default, a subscriber of an Amazon SNS topic receives every message published to the topic. A subscriber assigns a filter policy to the topic subscription to receive only a subset of the messages.
A filter policy is a simple JSON object. The policy contains attributes that define which messages the subscriber receives. When you publish a message to a topic, Amazon SNS compares the message attributes to the attributes in the filter policy for each of the topic`s subscriptions. If there is a match between the attributes, Amazon SNS sends the message to the subscriber. Otherwise, Amazon SNS skips the subscriber without sending the message to it. If a subscription lacks a filter policy, the subscription receives every message published to its topic.
Since the documentation clearly mentions this, all other options are incorrect.
For more information on message filtering, please refer to the below URL-
https://docs.aws.amazon.com/sns/latest/dg/message-filtering.html