What does the Analytic Solver Platform integer tolerance factor of $0$ accomplish?

Question $17$ options:

a$)$

It stops B & B after $100\%$ of all solutions are examined.

b$)$

It stops B & B when any feasible ILP solution is $0\%$ from the current ILP solution.

c$)$

It stops B & B when the true optimal integer solution has been found.

d$)$

It stops B & B when no more than $0\%$ of the changing cells have integer values.