Sentence Correction

Please correct the bolded part of the sentence, if necessary, with one of given options.

Improvements in economic theory and data gathering today makes possible more accurate to forecast than was possible even 20 years ago.

* today makes possible more accurate to forecast than was
* have made possible more accurate forecasts then were
* today have made possible more accurate forecasts than was
* today make possible more accurate forecasts than was
* today make possible more accurate forecasting that were

is it b?