Verify each option
A ---> 1/sinx=cscx -----> is not the answer
B ---> 1/cosx=secx ----> is the answer
C ---> cosx/tanx=cosx/(sinx/cosx)=cos^2x/sinx -----> is not the answer
D ---> tanx/sinx=(sinx/cosx)/sinx=1/cosx=secx -----> is the answer
E ---> cotxsinx=(cos/sinx)sinx=cosx ----> is not the answer
F ----> tanxcscx=(sinx/cosx)(1/sinx)=1/cosx=secx ----> is the answer
therefore
The answer is
options B, D and F