Bob connects to a company web site. his browser indicates that the digital certificate of the web site is valid. this application of encryption is an example of select one: a. public key infrastructure b. use of symmetric keys c. access control lists d. anti-spyware technology

The answer is a. Public key infrastructure

Explanation:

With Digital Certificates, businesses can utilise the security applications of PKI. Public Key Infrastructure allows a person or an organization to safely and securely exchange data over the internet.  With PKI offering that extra security between communications, we can maintain authentication, confidentiality, and Access Control. Once you have your website set, a Digital Certificate authority will first verify that you own a website and then sign their certificate so it it trusted by internet browsers