In IaaS model. operating system is managed by the customer

Containers are code execution environments that run within an operating system(for now), sharing and leveraging resources of that operating system. While a VM is a full abstraction of an operating system, a container is a constrained place to run segregated processes while still utilizing the kernel and other capabilities of the base 0S. Multiple containers can run on the same virtual machine or be implemented without the use of VMs at all and run directly on hardware.
Reference: CSA Security Guidelines V.4(reproduced here for the educational purpose)

One emerging architecture for hybrid cloud connectivity is "bastion" or "transit" virtual networks:
. This scenario allows you to connect multiple, different cloud networks to a data center using a single hybrid connection. The cloud user builds a dedicated virtual network for the hybrid connection and then peers any other networks through the designated bastion network.
. Second-level networks connect to the data center through the bastion network, but since they aren't peered to each other they can't talk to each other and are effectively segregated. Also, you can deploy different security tools, firewall rulesets, and Access Control Lists in the bastion network to further protect traffic in and out of the hybrid connection.
Reference: CSA Security GuidelinesV.4(reproduced here for the educational purpose)

The answer is False. This is a very tricky question and it has to be read and understood well before answering.
It is always the other way around. Cloud consumer's security increases when you move from Software as a service model to Infrastructure as a Service Model.

It is false. Platform security is a shared responsibility between cloud service provider and cloud service customer in Platform as a Service(PaaS) model.