In PKI, the public CA that issues certificates for multiple domains and is widely trusted as a root trust by operating systems and browsers is called

In PKI, the public CA that issues certificates for multiple domains and is widely trusted as a root trust by operating systems and browsers is called

• A. Third party CAs
• B. Root Certificate Authority
• C. Public Key Cryptography Standards
• D. Digital certificate

Answer: (A)

Public/third-party CAs are external authorities whose root certificates are pre-installed in operating systems and browsers, creating a trusted anchor that spans many domains. This type of CA issues certificates for numerous domains, enabling widespread trust across different clients and services. That broad trust and multi-domain issuance match the description, since browsers and OSes inherently trust these public roots to validate certificates on the web. In contrast, a Root Certificate Authority is the top-level trust anchor within a PKI, but the question emphasizes the issuer of certificates for many domains and being trusted as a root by systems, which points to the public/third-party CA more than to the isolated concept of a single root. Public Key Cryptography Standards refer to sets of standards rather than an issuing authority, and a digital certificate is the end-entity credential, not the issuer.

Public/third-party CAs are external authorities whose root certificates are pre-installed in operating systems and browsers, creating a trusted anchor that spans many domains. This type of CA issues certificates for numerous domains, enabling widespread trust across different clients and services. That broad trust and multi-domain issuance match the description, since browsers and OSes inherently trust these public roots to validate certificates on the web.

In contrast, a Root Certificate Authority is the top-level trust anchor within a PKI, but the question emphasizes the issuer of certificates for many domains and being trusted as a root by systems, which points to the public/third-party CA more than to the isolated concept of a single root. Public Key Cryptography Standards refer to sets of standards rather than an issuing authority, and a digital certificate is the end-entity credential, not the issuer.