Subset of knight's move in chess.

A particle is allowed to move in the $\mathbb{Z}\times \mathbb{Z}$ grid by choosing any of the two jumps:

1) Move two units to right and one unit up

2) Move two units up and one unit to right.

Let $P=(30,63)$ and $Q=(100,100)$, if the particle starts at origin then?

a) $P$ is reachable but not $Q$.

b) $Q$ is reachable but not $P$.

c) Both $P$ and $Q$ are reachable.

d) Neither $P$ nor $Q$ is reachable.

I could make out that the moves given are a subset of that of a knight's in chess. I think that it'd never be able to reach $(100,100)$ but I'm not sure of the reason. It has got to do something with the move of the knight but I cannot figure out what.

I don't have a very good idea about chess, so I'd be glad if someone could answer elaborately.

from Hot Weekly Questions - Mathematics Stack Exchange