Answer:
Potential energy of the system increases relative to infinity.
Step-by-step explanation:
Potential energy of two point charge is defined as,

Here,
are two point charge, r is the distyance between the two charges.
Now according to the question charge is of equal magnitude but opposite sign.
Therefore potential energy,

From the above formula if the distance increases then magnitude of potential energy decreases.
And due to presence of negative charge magnitude of Potential energy is increases with increasing distance.
Therefore, the potential energy is increasing if we move two opposite charge farther.