Final answer:
A Crypto Service Provider (CSP) is the entity responsible for calling crypto modules to perform cryptographic tasks such as encryption and decryption in applications.
Step-by-step explanation:
The entity that calls in crypto modules to perform cryptographic tasks is known as a Crypto Service Provider (CSP). The Crypto Service Provider is a software library that implements cryptographic algorithm and provides services to various applications. When an application requires encryption, decryption, signing, or any other cryptographic function, it requests these services from the CSP.
Other options like OCSP (Online Certificate Status Protocol), Certificate Authority (CA), and Intermediate CA have distinct roles in the cryptographic ecosystem. OCSP is used for obtaining the revocation status of an X.509 digital certificate, a CA issues digital certificates, and an Intermediate CA acts as a subordinate to a root CA issuing certificates and all are critical parts of PKI (Public Key Infrastructure).