These are the steps required to enable Salesforce as a SAML Identity Provider and use the App Launcher to access external applications. According to the Salesforce documentation1, you need to:

Enable Salesforce as a SAML Identity Provider with My Domain2.

Create aConnected App for each external application that you want to integrate with Salesforce3.

Add each Connected App to the App Launcher with a Start URL that points to the external application1.

Option B is incorrect because setting up an Auth Provider is not necessary for SAML SSO. Auth Providers are used for OAuth SSO, which isa different protocol4. Option D is incorrect because Identity Connect is a tool for synchronizing user data between Active Directory and Salesforce, which is not related to SSO or App Launcher5.