In WorldCupMatches table, we have the information of Away goals, and in the WorldCups table, we have the information of the Winner team and goal scored.
In WorldCups, there is only row for each year. But in WorldCupMatches, there is a separate row for each match. This is the perfect example to use blend as here we need to first aggregate the data from WorldCupMatches table.
Let's establish the blend relationship between these two data sources, on the basis of Country and Year.

Let's use WorldCups as the primary data source, so add the field from this data source to the view. Drop Year to Rows and change it discrete. Drop Country and Winner field as well to the rows.

In WorldCupMatches data source, create a calculated field :
Drop this field to the Text, and format it so that it will be shown in percentage.
Out of the given options, only in 1934 host country won the world cup

2010 is the correct answer.