In a two-dimensional motion, instantaneous speed v0 is a positive constant. Then which of the following are necessarily true?

Here it is given speed which is scalar quantity; therefore there is no sense of direction given. Hence we can’t say displacement in equal time intervals are equal, as we don’t know whether the object is moving in a straight line or uniform circular motion

Average acceleration will be zero only when an object is travelling in a straight line, it could without changing its speed, it is moving in a circular motion, which will have non-zero acceleration

When a particle is moving in a circular path with constant speed its average velocity will be zero (displacement will zero at the starting point)

Therefore, with a surety we can only say for constant speed is that it is covering equal path lengths in equal time intervals