What is the difference between ‘will’ and ‘going to’ when expressing future actions?

A. ‘Will’ is for expressing certainty, ‘going to’ is for expressing doubt.

B. ‘Will’ is for decisions made at the moment, ‘going to’ is for pre-planned intentions or predictions.

C. ‘Will’ is for past actions, ‘going to’ is for present actions.

D. ‘Will’ is for singular subjects, ‘going to’ is for plural subjects.