If you mean the one about gamma beta and alpha radiation...
The ray B if I'm not mistaken was Gamma due to the fact it was not deflected by the magnetic field and it had the greatest number of counts because it has the weakest Ionizing Effect.
The one deflected upwards was Alpha, as you could check with the Left Hand rule. It also had the least amount of counts because of it's strong ionizing effect
And the one deflected down was Beta as you could also check with the Left Hand Rule and with the number of counts
Not entirely sure if those are the correct answers but I think they are
The ray B if I'm not mistaken was Gamma due to the fact it was not deflected by the magnetic field and it had the greatest number of counts because it has the weakest Ionizing Effect.
The one deflected upwards was Alpha, as you could check with the Left Hand rule. It also had the least amount of counts because of it's strong ionizing effect
And the one deflected down was Beta as you could also check with the Left Hand Rule and with the number of counts
Not entirely sure if those are the correct answers but I think they are