$-4.3$, $-9.97$, and $$-\frac{20}{21}$$ are negative numbers. 
Among these numbers, $-4.3$, $$12\%$$, $0$, $$\frac{2}{5}$$, $-9.97$, $$-\frac{20}{21}$$, how many numbers are negative? 
Options:
1: two 
2: three 
3: four 
4: five 