Answer:
c.Beta (1 e-) is the answer.
Because it’s made of metal. And metal is a good conductor
Answer:
The length of the tube is 3.92 m.
Explanation:
Given that,
Electric potential = 100 MV
Length = 4 m
Energy = 100 MeV
We need to calculate the value of 
Using formula of relativistic energy

Put the value into the formula


Here, 



We need to calculate the length
Using formula of length

Put the value into the formula


Hence, The length of the tube is 3.92 m.
D Because If Your Going To Have A Contest Its Ganna Have To Be The Same Objectives For Both Contenders