Step 1: Understanding Gauss's law in magnetostatics.
Gauss’s law in magnetostatics states that the magnetic flux through any closed surface is zero, i.e., the net magnetic field lines entering any closed surface is zero, which can be mathematically written as:
\[
\oint \vec{B} \cdot d\vec{S} = 0
\]
This implies there are no "magnetic charges," and the magnetic field is always solenoidal (no beginning or end).
Step 2: Conclusion.
Thus, the correct expression for Gauss's law in magnetostatics is option (1).
\[
\boxed{(1) \, \oint \vec{B} \cdot d\vec{S} = 0}
\]