In this model of cloud computing, the cloud provider manages authentication, including multi$-$factor authentication options $($like Duo, for example$)$

Question $2$ options:

Platform$-$as$-$a$-$Service $($PaaS$)$

Software$-$as$-$a$-$Service $($SaaS$)$

Infrastructure$-$as$-$a$-$Service $($IaaS$)$

Identity$-$as$-$a$-$Service $($IDaaS$)$