The answer for this question is D.
The way I would explain it is quite difficult to understand, so this is what Google says. "The wavelength (or equivalently, frequency) of the photon is determined by the difference in energy between the two states. These emitted photons form the element's spectrum. The fact that only certain colors appear in an element's atomic emission spectrum means that only certain frequencies of light are emitted." I hope this helped.
Arenal Volcano: Plate Tectonic Setting. The volcanic arc of Costa Rica, where Arenal is located, is a chain of mountains resulting from the subduction of the Cocos tectonic plate under the Caribbean Plate. Costa Rica is part of the Central American isthmus, which connects the North and South American continents.
For the first one the answer is B. and the second one is D.
