an electron is shot into a liquid placed in uniform magnetic field in a plane perpendicular to magnetic field

a the trajectory of electron is circular.

b the trajectory is inward winding spiral.

c kinetic energy is constant.

d none.

Liquid is the medium here..
So, the path of the electron will be just like as that of the path taking medium as air or as vaccum.
Now think on your own, that could have been the path if the medium was air? The same path will be followed by the electron here in liquid also..
Hope you get it :) :)