One of the challenges of tidal wave energy is: the start-up costs are expensive. the materials needed to couple the tidal energy to electricity are rare. the tides are very unpredictable. as global warming increases, the tides will diminish.

One of the challenges of tidal wave energy is the start-up costs are expensive. Because it needs materials that do not erode quickly and can withstand the pressure of the incoming waves. This is another form of a renewable source of energy.

it is the second option.

you'd use the equation that establishes a relationship between  energy  and  wavelength, which looks like this

e=h⋅cλ, where

λ  - the wavelength of the photon; c  - the speed of light, usually given as  3⋅108m/s; h  -  planck's constant, equal to  6.626⋅10−34j s

plug the value you were given for the energy of the photon in the above equation to get the wavelength

e=h⋅cλ⇒λ=h⋅ce

λ=6.626⋅10−34js⋅3⋅108ms−1.257⋅10−24j=1.581⋅10−1m