The law of charges states that, like charges repel while unlike charges attract.
It is also important field lines move from positive to negative.
From what we can see in the diagram, the field lines are moving away from the 2 charged particles p and q. This tells us that the two charges are positively charged.
Since, the two charges are having the same charge, they repel.
The best description of the charges is, D.) they are positive, they repel