This is a great problem for practicing percentage change calculations!
The correct answer is (B) $\(28.6 \)%$.
Here is the step-by-step calculation:
1. Calculate the Absolute Increase

First, find out how much the membership increased:

$$
\(\begin{gathered}
\text { Increase }=\text { New Membership - Original Membership } \\
\qquad \text { Increase }=225-175=50
\end{gathered}\)
$$

2. Calculate the Percent Increase

Next, use the percent increase formula, which is the Increase divided by the Original Value, times 100%:

$$
\(\begin{gathered}
\text { Percent Increase }=\frac{\text { Increase }}{\text { Original Membership }} \times 100 % \\
\text { Percent Increase }=\frac{50}{175} \times 100 %
\end{gathered}\)
$$

3. Simplify and Convert to Percentage

Simplify the fraction $\frac{50}{175}$ by dividing both the numerator and denominator by 25 :

$$
\(\frac{50 \div 25}{175 \div 25}=\frac{2}{7}\)
$$


Now, convert the fraction $\(\frac{2}{7}\)$ to a decimal:

$$
\(\frac{2}{7} \approx 0.2857\)
$$


Multiply the decimal by $\(100\) %$ to get the percentage:

$$
\(0.2857 \times 100\) % \(\approx 28.57\) %
$$


Rounding to one decimal place gives us $\(28.6\) %$, which matches option (B).