What is chain reaction fission of uranium 235?

Question : Two elements which are used to absorb neutrons to control the chain reaction during nuclear fission are

Option 1: Boron and Cadmium

Option 2: Boron and Plutonium

Option 3: Cadmium and Uranium

Option 4: Uranium and Boron

Question : Name the particle that is most essential to continue the chain reaction during the fission of uranium

Option 1: Electron

Option 2: Proton

Option 3: Neutron

Option 4: Positron

Question : Hydrogen bomb is based on the principle of

Option 1: controlled fission reaction

Option 2: uncontrolled fission reaction

Option 3: controlled fusion reaction

Option 4: uncontrolled fusion reaction