To determine how many times larger \( 4 \times 10^{12} \) is than \( 2 \times 10^{9} \), we divide the two quantities.
\[
\frac{4 \times 10^{12}}{2 \times 10^{9}} = \frac{4}{2} \times \frac{10^{12}}{10^{9}}
\]
Calculating the first part:
\[
\frac{4}{2} = 2
\]
For the second part, we use the rule of exponents \( \frac{10^{a}}{10^{b}} = 10^{a-b} \):
\[
\frac{10^{12}}{10^{9}} = 10^{12-9} = 10^{3}
\]
Now, combine both parts:
\[
2 \times 10^{3} = 2 \times 1000 = 2000
\]
Thus, \( 4 \times 10^{12} \) is 2000 times larger than \( 2 \times 10^{9} \).
The answer is \( \text{B. } 2,000 \).