Formulae
1. Percent Increase from $A$ to $B$ :

$$
\(\frac{\text { Increase }}{\text { Original Amount }} \times 100=\frac{B-A}{A} \times 100\)
$$

2. Percent Decrease from $B$ to $A$ :

$$
\(\frac{\text { Decrease }}{\text { Original Amount }} \times 100=\frac{B-A}{B} \times 100\)
$$


Quantity A: Percent Increase from 11 to 16
The amount of change (increase) is $16-11=5$. The original amount is 11 .

Quantity $\(\mathrm{A}=\frac{5}{11} \times 100\)$

Quantity B: Percent Decrease from 16 to 11
The amount of change (decrease) is $16-11=5$. The original amount is 16 .

$$
\(\text { Quantity } B=\frac{5}{16} \times 100\)
$$


Comparison
We are comparing two fractions, $\(\frac{5}{11}$ and $\frac{5}{16}\)$.
Since the numerators are the same (5), the value of the fraction is determined by the denominator. A smaller denominator results in a larger fraction.

$$
\(11<16 \Longrightarrow \frac{5}{11}>\frac{5}{16}\)
$$


Therefore, Quantity A is greater than Quantity B.
The correct choice is $\(\mathbf{A}\)$.