Which hosted solution is an example of a cloud vendor who installs and manages the data center, server and network hardware, operating system, application, and database?

Question $34$ options:

a$)$ software$-$as$-$a$-$service $($SaaS$)$

b$)$ infrastructure$-$as$-$a$-$service $($IaaS$)$

c$)$ platform$-$as$-$a$-$service $($PaaS$)$

d$)$ data center$-$as$-$a$-$service $($DaaS$),$

whats the correct answer