Which setup win meet the requirements?

You have recently joined a startup company building sensors to measure street noise and air
quality in urban areas. The company has been running a pilot deployment of around 100
sensors for 3 months each sensor uploads 1KB of sensor data every minute to a backend
hosted on AWS. During the pilot, you measured a peak or 10 IOPS on the database, and you
stored an average of 3GB of sensor data per month in the database.
The current deployment consists of a load-balanced auto scaled Ingestion layer using EC2
instances and a PostgreSQL RDS database with 500GB standard storage.
The pilot is considered a success and your CEO has managed to get the attention or some
potential investors. The business plan requires a deployment of at least 1O0K sensors which
needs to be supported by the backend. You also need to store sensor data for at least two
years to be able to compare year over year Improvements.
To secure funding, you have to make sure that the platform meets these requirements and
leaves room for further scaling. Which setup win meet the requirements?

A.
Add an SOS queue to the ingestion layer to buffer writes to the RDS instance

B.
Ingest data into a DynamoDB table and move old data to a Redshift cluster

C.
Replace the RDS instance with a 6 node Redshift cluster with 96TB of storage

D.
Keep the current architecture but upgrade RDS storage to 3TB and 10K provisioned IOPS

Explanation:
The POC solution is being scaled up by 1000, which means it will require 72TB of Storage to
retain 24 months worth of data. This rules out RDS as a possible DB solution which leaves
you with RedShift.
I believe DynamoDB is a more cost effective and scales better for ingest rather than using
EC2 in an autoscaling group.
Also, this example solution from AWS is some what similar for reference.
http://media.amazonwebservices.com/architecturecenter/AWS_ac_ra_timeseriesprocessing_
16.pdf