Answer:
1.2826 x 10^-13 m
Explanation:

Here, k be the kinetic energy and m be the mass
K = 50 KeV = 50 x 1.6 x 10^-16 J = 80 x 10^-16 J
m = 1.67 x 10^-27 kg

λ = 1.2826 x 10^-13 m
The properti that you didnt share
A would be the correct answer. Its the only one to make sense since you are trying to solve the conflict!
Answer:
constant volicty of the pumper when they hit ground 7.03-/s