Bacterial cultures start with $1.0\times 10^6$ cells per mL. Drug W or drug X is added at 0 h and washed out at 6 h. With W the count is $1.1\times 10^6$ at 6 h and $9.0\times 10^6$ at 12 h. With X the count is $2.0\times 10^2$ at 6 h and $3.0\times 10^2$ at 12 h. Which conclusion is correct?

1. ABoth W and X are bactericidal
2. BW is bactericidal and X is bacteriostatic
3. CBoth W and X are bacteriostatic
4. DW is bacteriostatic (like chloramphenicol) and X is bactericidal (like an aminoglycoside)