Final answer:
The element of Burke's pentad foregrounded when Trump says 'we will build new roads and highways' is the 'act,' as it describes the action taking place, which is the construction of new roads and highways.
Step-by-step explanation:
When analyzing the statement "we will build new roads and highways" using Kenneth Burke's pentad, we focus on the elements of act, scene, agent, agency, and purpose. The element being foregrounded in this statement is the act, which refers to what is happening, or the action that is taking place. In this context, the act is the construction of new roads and highways. Burke's pentad is a tool for dissecting the motivations and meanings behind rhetoric and expression, and in this case, the act of building conveys progress and development, which could be aligned with larger themes like economic growth or modernization. Aspects like scene (the physical or social context), agent (who is involved), agency (the means through which the act is accomplished), and purpose (the goal or reason behind the action) are subsidiary to the primary focus on the act of building in this particular statement.