Step 1: Understanding the relation.
The total magnetic field \( B \) is related to the magnetic intensity \( H \) by the equation:
\[
B = \mu_0 (H + M)
\]
where \( M \) is the magnetization. The magnetization \( M \) is related to the magnetic susceptibility \( x \) by:
\[
M = xH
\]
Substituting this into the equation for \( B \), we get:
\[
B = \mu_0 (H + xH) = \mu_0 H (1 + x)
\]
Thus, the relation is:
\[
\frac{B}{H} = \mu_0 (1 + x)
\]
Step 2: Conclusion.
Thus, the correct answer is (A) \( \frac{B}{H} = \mu_0 (1 + x) \).