Cosmic Microwave Background radiation is one piece of supporting evidence for the Big Band Theory. Are these microwaves at the longer or shorter end of the spectrum? are they long or short?

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.