Question

When an airplane increases its thrust, which of the following could happen

Answer 1

In normal steady flight, thrust = drag, and lift = weight.
If velocity is gained, the wing will increase lift, so the aircraft will climb.
As velocity has increased, drag will also increase but at a faster rate, i.e. if you were to double velocity, drag will increase to the square of its starting value.
The aircraft will not spin out of control.
Its weight will not increase.