Step 1: Understand the question.
We must name the cloud-based document storage and verification platform of India.
Step 2: Break down the clue.
Cloud-based means stored online. Document storage and verification means you can keep and prove official papers like certificates online. This points to a government digital service.
Step 3: Check the options.
WhatsApp and Instagram are chat and social media apps, not document lockers. Puramitra is not a document platform. So these do not fit.
Step 4: Identify the right service.
DigiLocker is the Government of India platform that lets citizens store and verify documents online, as part of Digital India.
Step 5: Confirm the match.
Since DigiLocker exactly matches storing and verifying official documents in the cloud, it is the answer.
Step 6: Match with the options.
The first option, Digilocker, is correct.
\[ \boxed{\text{Digilocker}} \]