Consider the three choices (i), (ii), and (iii) to complete the sentence below. Select the answer that contains all of the correct choices but no incorrect choices.
The momentum of a system is constant
(i) if there is no net external force
(ii) if there are no external forces (the system is isolated)
(iii) always
Group of answer choices
(i) only
(i) and (ii) only
(ii) only
(i), (ii), and (iii)