The diagram shows two charged objects, A and B.

2 balls separated horizontally. Lines with arrowheads run from the left ball labeled A to the right ball labeled B, curving more and more outward and then inward as they occur further from the shortest line connecting the balls. Curved lines with arrowheads point to the right ball from the right and from the left ball to the left.
Based on the field lines, what are the charges of the objects?

A: positive
B: negative

A: negative
B: positive

A: negative
B: negative

A: positive
B: positive