Answer:
2 The field gets weaker.
Step-by-step explanation:
The magnetic field produced by a current-carrying wire is given by:

where
is the vacuum permeability
is the current in the wire
is the distance from the wire
In this problem, the battery weakens, so the current through the wire decreases. As
(the current) is on the numerator in the formula, it means that the value of the fraction decreases, so the magnetic field gets weaker (in fact, the magnetic field is directly proportional to the current, so as the current decreases, the intensity of the field decreases as well).