The possible times it can be d distant from origin are 0,2,4.
Hence option (c)
The paritcle has its acc perpendicular to its vel and antiparallel to it.
It will describe a motion in 2 phases ;
A> The tangential vel will continiously decrease and since centrepetal acc is cont, radius will keep decreasing and the trajectory would be that of a regularly collasping circle. Once the tangential vel becomes zero...phase B starts
B> the particle retraces its path and now the vel is ever increasing, since centripetal acc is const - r is now ever increasing.