Answer: D and E.
Option A is INCORRECT.
Data is available for up to the last 12 months.
Option B is INCORRECT.
Cost explorer provides Usage-Based Forecasting not a forecast for the next 12 months.
Option C is INCORRECT.
A recommendation is provided to purchase the Reserved instances.
Option D is CORRECT as Cost explorer provides custom usage forecasts to gain a line of sight into your expected future costs.
Option E is CORRECT