Definition formula for momentum: P = mv
So P(A) = 0.45 * 50 = 22.5 kgm/s
P(B) = 0.45 * 80 = 36 kgm/s
P(C) = 0.45 * 25 = 11.25 kgm/s
B has the greatest momentum
Let the rescue boat starts at an angle theta with the North
now its velocity towards East is given as


now in some time "t" it will catch the boy
so we will have

also we have

now we have



by solving above we got

Explanation:
The charge on the electron is, 
The electric field at a distance r from the electron is :

Where
k is the electrostatic constant, 
We know that the electric field lines starts from positive charge and ends at the negative charge. Also, for a positive charge the field lines are outwards while for a negative charge the field lines are inwards.
So, the correct option is " the electric field is directed toward the electron and has a magnitude of
. Hence, this is the required solution.