A company is planning to develop an application that is going to make use of a DynamoDB table. The structure of the table is given below.
Attribute Name
Type
Description
Product ID
Number
Unique ID of product
Review ID
Number
Unique ID of an optional customer review
Product Name
String
Name of the product
Product Description 
String
Description of the product
Which of the following should be chosen as the partition key to ensure the MOST effective distribution of keys?

Answer options:

A.Product ID
B.Review ID
C.Product Name
D.Production Description

Answer – A
The most effective one will be the Product ID since you have a unique ID for each product.
Option A is correct. 
Option B is incorrect because reviews are optional (as stated in the question). So we can`t guarantee where reviews will be present.
Options C and D are incorrect since it would not be best to keep these as the partition keys.
For more information on DynamoDB and partition keys, please refer to the below URLs-
https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/best-practices.html
https://aws.amazon.com/blogs/database/choosing-the-right-dynamodb-partition-key/