Question: "Only what demographic can use these funds?"

Context: "Various benefactions make it possible to give grants each year to boys who wish, for educational or cultural reasons, to work or travel abroad. These include the Busk Fund, which supports individual ventures that show particular initiative; the C.M. Wells Memorial Trust Fund, for the promotion of visits to classical lands; the Sadler Fund, which supports, amongst others, those intending to enter the Foreign Service; and the Marsden Fund, for travel in countries where the principal language is not English."

Answer:
boys
The question asks "Only what demographic can use these funds?" The context describes various benefactions that make it possible to give grants each year. In the context, only boys are described as being able to receive these grants for travel and work abroad. 
Therefore, based on the information given in both the question and text, we deduce that only this particular group of people has access to these funds: Boys.