D Question 2 0.5 pts If you are building a forecasting model of the SPSCIU [main US equity' market]. what would be the most appropriate basis functions to simulate the particular effects of the 1'99? Asian crisis, the credit crisis of 2008. and the Covid crisis of 2020? (:1: Original data without transformation C} Fourier transforms C} Step functions {3: None of the other options (:1: Polynomial functions