Suppose There Was a Debate Regarding How to Spend $1

Suppose there was a debate regarding how to spend $1 billion in newly found revenues in the budget. Suppose the centrist Democrat suggests an increase to infrastructure spending. Suppose the centrist Republican suggests an increase in cyber-defense spending. The Democrat says that the extra infrastructure spending will decrease travel times and be the most valuable. The Republican is arguing that, on average, cyber-security is worth the money so more is better. What is going on here?

A) Both are employing marginal analysis, just from different perspectives
B) Only the Democrat is using marginal analysis.
C) Only the Republican is using marginal analysis.
D) Neither are using marginal analysis.