The correct answer is A. Amazon Elastic MapReduce (EMR) is a cloud-based big data platform for processing vast amounts of data using open source tools such as Apache Hadoop, Apache Spark, and Presto. EMR is built on top of Amazon Elastic Compute Cloud (EC2), which provides resizable compute capacity in the cloud.
Amazon Mechanical Turk (MTurk) is a crowdsourcing marketplace that enables businesses and individuals to coordinate the use of human intelligence to solve a wide range of tasks. MTurk is not built on top of a Hadoop framework.
Amazon DevPay is a web service that enables developers to accept payments for digital goods and services. DevPay is not built on top of a Hadoop framework.
Multi-Factor Authentication (MFA) is an authentication method that requires users to provide two or more forms of identification in order to access a system. MFA is not built on top of a Hadoop framework.