Which one was/is used as a fumigant pesticide ?

Which of the following is used in fumigation.

Which of the following bacteria is used extensively as a bio - pesticide ?

Which one of the following types of pesticides is convenient to control stored grain pests?

Aluminium phosphide (cellphos) is used as fumigant (killing insects and pests) because in the presence of moisture it gives

Which of the following is gaseous fumigant ?

Which one of the following is a pesticide?

Which one of the following pairs is the strongest pesticide ?