If you are out rowing in a boat, you should be most concerned if you see a wave with which characteristic?
a. low frequency
b. high frequency
c. large amplitude
d. small amplitude

I assume the answer this question is looking for would be a large amplitude.

Small amplitude and low frequency do not make sense as if the amplitude is smaller it would has less effect on the boat, this logic is the same with a low frequency.

A high frequency would cause more waves to effect the boat which could effect the boat, but it could be a wave with a small amplitude (a smaller wave) that may not effect the boat as much. So if one million waves with microscopic amplitudes interacted with the boat you wouldnt really feel the effect which is why the frequency doesnt matter here.

Now, if you had a larger amplitude wave, the boat could tip. Imagine if one really big ocean wave hit a boat. If that wave hit the boat it is possible it could tip. Therefore, amplitude appears to be the most detrimental for boaters.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia