A magnetic field does not have any influence on wind. The Coriolis effect, pressure gradient, and friction do affect wind.
The solution is B.
343.1484 grams. this is your answer.
On ground weight of plane will be measured as its actual weight which will be given as

now when plane is in air its weight is measured as combined effect of earth gravitational force and buoyancy force both
so weight in air will be given as

here since net effect due to air is opposite to the direction of weight so in air the plane weight will be measure less than its weight on ground.
so answer will be
A)more than a plane in the air