In this case three configurations will be required each for port 8000, 6000 and 7000.
There would be three global elements defined for HTTP connections.
Each HTTP connection will have host and port. One example shown below with host as localhost and port 6000

To use an HTTP listener, you need to declare a configuration with a corresponding connection. This declaration establishes the HTTP server that will listen to requests.
Additionally, you can configure a base path that applies to all listeners using the configuration.
<http:listener-config name="HTTP_Listener_config" basePath="api/v1">
<http:listener-connection host="0.0.0.0" port="8081" />
</http:listener-config>
https://docs.mulesoft.com/http-connector/1.6/http-listener-ref#http-listener-configuration

For Each Scope
The For Each scope splits a payload into elements and processes them one by one through the components that you place in the scope. It is similar to a for-each/for loop code block in most programming languages and can process any collection, including lists and arrays. The collection can be any supported content type, such as application/json, application/java, or application/xml.
General considerations about the For Each scope:
By default, For Each tries to split the payload. If the payload is a simple Java collection, the For Each scope can split it without any configuration. The payload inside the For Each scope is each of the split elements. Attributes within the original message are ignored because they are related to the entire message.
For Each does not modify the current payload. The output payload is the same as the input.
Mule Doc Reference : https://docs.mulesoft.com/mule-runtime/4.3/for-each-scope-concept

Option1 is correct syntax to configure HTTP Listener endpoint

Keyword to ad function in Dataweave transformation is fun. Hence option 2 and 4 are invalid. Also parameters needs to be passed exactly in same order as defined in function definition. Hence correct answer is' fun addKV( object: Object, key: String, value: Any) = object ++ {(key):(value)}
---
addKV ( {"hello': "world"}, "hola", "mundo" )
MuleSoft Documentation Reference : https://docs.mulesoft.com/mule-runtime/4.3/dataweave-functions DataWeave Function Definition Syntax To define a function in DataWeave use the following syntax:
fun myFunction(param1, param2, ...) = <code to execute>
The fun keyword starts the definition of a function.
myFunction is the name you define for the function.
Function names must be valid identifiers.
(param1, param2, ... , paramn) represents the parameters that your function accepts.
You can specify from zero to any number of parameters, separated by commas (,) and enclosed in parentheses.
The = sign marks the beginning of the code block to execute when the function is called.
<code to execute> represents the actual code that you define for your function.

File is not updated when FTP read operations is performed.
MuleSoft Doc Ref : https://docs.mulesoft.com/file-connector/1.3/file-read