l remember we have learnt something realted to the angle of pendulum but l don't clearly remember as far as l know if the angle of pendulum is too big then there will be an error or something so can someone please explain me what it actually means​

Which of the following situations is impossible? a) an object has velocity directed east and acceleration directed east. b) an object has zero velocity but non-zero acceleration. c) an object has constant non-zero velocity and changing acceleration. d) an object has velocity directed east and acceleration directed west. e) an object has constant non-zero acceleration and changing velocity.