A Company Designs a Mobile App for Its Customers to Upload

A company designs a mobile app for its customers to upload photos to a website. The app needs a secure login with multi-factor authentication (MFA) . The company wants to limit the initial build time and the maintenance of the solution. Which solution should a solutions architect recommend to meet these requirements?

A) Use Amazon Cognito Identity with SMS-based MFA.
B) Edit IAM policies to require MFA for all users.
C) Federate IAM against the corporate Active Directory that requires MFA.
D) Use Amazon API Gateway and require server-side encryption (SSE) for photos.