We certainly offered the trust (probably the power of decision to obey or not to obey the orders of Allah) to the skies and the earth and the mountains, but they refused to bear it and became afraid of it, and man (undertook the responsibility of) bearing it (but) he was certainly unjust, ignorant,
The ‘Trust’ may be the power of obeying and implementing the orders of Allah (SWT) as ‘Kalifa’ 2:30, with the choice of disobeying. This choice of disobedience is given only to man and jinn [Iblis disobeyed Allah (SWT) 7:12] the rest of the creation does not appear to have this choice. Man took up the responsibility but disobeyed, therefore those who broke the promise will be punished and those who kept it, will be rewarded.