ERROR: Option Strict On disallows implicit conversions from 'System.Collections.Generic.IEnumerable(Of String)' to 'String'

I am trying to unzip an attachment that was downloaded from email.
From the activity “Save attachment” mail is set as input and the variable attachment as output. Datatype of this output is IEnumerable.
Meanwhile, in the next activity where the attachment is supposed to be extracted, as input it is the variable attachment (IEnumerable) and as output it is the variable extract (Directory Info).
When I try to run the sequence, I get an error in the 2nd activity where attachment (input is entered). Error: Option Strict On disallows implicit conversions from ‘System.Collections.Generic.IEnumerable(Of String)’ to ‘String’.
Should I change the datatypes of any of the variables?